Math Central - mathcentral.uregina.ca
Quandaries & Queries
Q & Q
. .
topic card  



list of
. .
start over

91 items are filed under this topic.
20+30*0+1=? 2016-12-26
From Mr:
Answered by Penny Nom.
Order of operations 2015-09-12
From Tanisha:
I would just like to double check if something like 5x squared times 4x cubed equals 20x to the power of 5??
It's just that we were told you can only answer an equation like this if the base is the same...so does that mean the x part or the whole thing like 5x? I'm sorry if that didn't make sense!

Thank you for your help!!

Answered by Penny Nom.
What is 20 and 3/5 of 10? 2014-11-26
From Jeannine:
What is 20 and 3/5 of 10? Question is written exactly this way. Is this 20 3/5 times 10 (103/5 times 10), or is it 20 and (3/5 times 10)?
Answered by Penny Nom.
50+9-13 multiplied by 2= 2014-06-25
From Adrian:
50+9-13 multiplied by 2=
Answered by Penny Nom.
Order of operations 2014-02-04
From Alex:
Hi there,i got problem with order of operation.Can you please help to find a solution for this?
Thank u beforehand

Answered by Penny Nom.
Is this operation associative? 2014-01-14
From patrick:
Associative test: Can you explain the following to me?

Is the following operation associative?: x*y=x+y+1
1) x*(y*z)=x*(y+z+1)=x+(y+z+1)+1=x+y+z+2
2) (x*y)*z=(x+y+1)*z=(x+y+1)+z+1=x+y+z+2

The answer is yes as 1) = 2)

My specific questions are:
1) How x*(y*z)=x*(y+z+1)=x+(y+z+1)+1 ?
2) How (x+y+1)*z=(x+y+1)+z+1?

Thank you!!

Answered by Penny Nom.
A sequence of operations, in order 2013-09-20
From jen:
multiply 46x23
add 342
divide by 70
subtract 5
I not sure what the answer is..i need to know the answer..thanks..

Answered by Penny Nom.
A messy arithmetic expression 2013-02-24
From niiaryee:
Answered by Penny Nom.
4*4+4*4+4-4*4=??? 2013-02-06
From Jacky:
Answered by Penny Nom.
3x6)+(12divided by2)-8= ? 2012-12-17
From christina:
hi my question that's been bothering me is what's
(3x6)+(12divided by2)-8= ?????

Answered by Penny Nom.
4+4x5+4= ? 2012-10-31
From Bob:
4+4x5+4= ?
Answered by Harley Weston.
5 + 5 + 5 - 5 + 5 + 5 - 5 + 5 x 0 = 2012-07-29
From Tom:
5 + 5 + 5 - 5 + 5 + 5 - 5 + 5 x 0 =
Answered by Harley Weston.
9-3(2+6)/6-2*5 2012-06-08
From Sammi:
Hi there,

I am doing a practice test for my admittance into a college accounting program and I am really confused by this equation.

The answer I got was way off what the test answer sheet says it should be.

The question is


If you could explain how the answer beccomes 35 that would be greatly apprciated!!

Thank you!

Answered by Robert Dawson.
- 16 x 6 / -2 2011-09-09
From Nadiyah:
i dont understand how to answer this question ;
- 16 x 6 / -2
i still dont understand it with bedmas
/ = divison
please help!

Answered by Penny Nom.
PEDMAS 2011-04-10
From Ross:
48 ÷ 2 (9+3)

Is the answer 2 or 288?

Answered by Harley Weston.
Order of operations 2010-02-07
From addie:
(3+10) x 10 - 8 x 4 =
Answered by Penny Nom.
(24x3)+(7x8)-(20/5)+(4x7) 2009-12-01
From Marilyn:
Thought I had the answer but the form says no. Could you solve it for me please.

Answered by Penny Nom.
-4 squared and (-4) squared 2009-09-29
From Andrea:
Is -4 squared the same as (-4) squared? I am thinking the first is -16 and the second is +16. I am trying to clarify for my students.
Answered by Penny Nom.
Evaluating -x^2 + (yz - 3)^2 2009-09-28
From Kathy:
My daughter and I are having trouble solving this equation:

-x²+ (yz – 3)²

if x=-4,y=2 and z=0 We are having difficulty with the -x² part of the equation. Thanks

Answered by Penny Nom.
Order of operations 2009-09-24
From aman:
my question is regarding the fact i have a formula which looks like this :

(ratio 1 + ratio 2 divided by 2)

so my question is do i add first then divide by 2 or do it all together

Answered by Penny Nom.
5 x 8 + 6 divided 6 - 12 x 2 2009-09-24
From Susan:
5 x 8 + 6 divided 6 - 12 x 2. I am not sure of the rules of operation for this type of question
Answered by Penny Nom.
Number & Operation Puzzle 2009-06-12
From Francine:
How can I get the number 26 using 1,2,3,4,&5 and using addition, subtraction, multiplication and division. Each operator and digit must be used exactly once. My son presented me this question and I can't determine if it's even possible.
Answered by Janice Cotcher.
Augmented matrix: independent, dependent, or inconsistent? 2009-02-23
From Anna:
Perform row operations on the augmented matrix as far as necessary to determine whether the system is independent, dependent, or inconsistent.

x + y + z = 11
x - y + 3z = 5
2x + 2y + 2z = 15

Answered by Harley Weston.
Using the augmented matrix 2008-10-17
From Karlena:
I am supposed to write the augmented matrix of the system and use the matrix method to solve the system. I must show my work algebraically


Answered by Harley Weston.
An associative binary operation 2008-09-08
From Skye:
Suppose that * is an associative binary operation on a set S. Show that the set H={a E S such that a*x=x*a for all x E S} is closed under *. (We think of H as consisting of all elements of S that commute with every element in S.) Thanks!
Answered by Harley Weston.
Is this operation associative? 2008-09-06
From Francesca:
Determine whether the binary operation * defined is commutative and whether * is associative * defined on Z by a*b = a-b\ I understand how to figure out if it's commutative, but I thought for a binary operation to be associative, it had to have at least three elements, so I don't know how to tell if this associative or not.
Answered by Penny Nom and Victoria West.
BEDMAS 2008-08-12
From Rebecca:
I have 3 questions. 1) I don't really understand BEDMAS.Im going in to the 6th grade and im kind of nervis about it.? 2)When you're doing BEDMAS what does the small 3 or 2 above the other numerals mean? 3)How would you answer this:5+2 x 9 - 9 x 12= ??
Answered by Janice Cotcher.
Why does -2^2 = -4 when -2 * -2 = 4? 2008-04-22
From blaine:
Why does -2^2 = -4 when -2 * -2 = 4?
Answered by Penny Nom.
10 - 3 + 2 2008-02-21
From Amrit:
what 10-3+2

is it 5 or 9

Answered by Penny Nom.
Numbers and Operations 2008-02-02
From Charlotte:
On the TABE (Test for Adult Basic Education) test, one of the categories is number operation. I would like to know what consist of number operation.
Answered by Penny Nom.
An augmented matrix 2007-11-29
From Beth:
I am having troubles fiinding this augnmented matrix. I know how to do it but everytime i do it it get a different answer and its not the right answer. Could you help me to make sure I do it right?

Here is the problem:
4x - 3y = 5
2x +9y = 6

Answered by Harley Weston.
(32-2 x 5) divided by 2 + 8 2007-11-28
From Kim:

(32-2 x 5) divided by 2 + 8

Answered by Leeanne Boehm.
Order of operations 2007-10-17
From Devon:
What function precedes the other? ie; 18 - 4 x2 =
Answered by Penny Nom.
15 divided by 5a 2007-10-12
From Susan:
Is "5a" considered an expression to be solved first, or do you simply go in PEMDAS order with the 15 divided by 5 in the following problem: Evaluate when a = 2 15 divided by 5a
Answered by Penny Nom.
Simplifying algebraic expressions 2007-10-09
From Sakeena:
Answered by Stephen La Rocque.
Solving arithmetic problems in the right order (BEDMAS) 2007-10-05
From Kim:
3+4x2-(10 divided by 5)= what?
Answered by Penny Nom.
A binary operation 2007-07-31
From sofia:
Prove that if * is associative and commutative binary operation on a set S, then (a*b)*(c*d) = [(d*c)*a]*b

for all a,b,c,d element in S. Assume the associative Law only for triples as in the definition that is, assume only (x*y)*z = x*(y*z) for all x,y,z element in S.

Answered by Penny Nom.
Binary operations 2007-07-30
From jim:
prove or disprove:

Every binary operation on a set consisting of a single element is both commutative and associative.

Answered by Penny Nom.
Is -2^2 = -4 or 4? 2007-01-23
From Joan:
Is -2 squared, when written without parentheses around the -2, -4 or could this correctly be solved by squaring -2 (-2 x -2) for an answer of 4? Or, to correctly get an answer of 4, would the problem have to read (-2) squared?
Answered by Stephen La Rocque.
Answer to skill testing question 2007-01-18
From Mike:
This question was on a ballot. Is the right answer 36 or 1? 5+2-1X6=
Answered by Stephen La Rocque.
Fill in the signs 2006-12-07
From Ujwala:
4$4$4$4=20 Fill in the signs in the place of dollor symbol.
Answered by Stephen La Rocque.
(2324/4)-525+214 2006-10-15
From Sherin:
Answered by Penny Nom.
BEDMAS 2006-09-24
From Partick:
if you have a question like this
how do you solve it step by step

Answered by Penny Nom.
what is 8+(-2)(-5)/4-(-1)-4(-2+3) 2006-09-08
From Jordan:
what is 8+(-2)(-5)/4-(-1)-4(-2+3)
Answered by Paul Betts.
16X27+32÷4-26 2006-08-20
From Amanda:
The question was 16X27+32÷4-26.
Answered by Stephen La Rocque.
Order of operations 2006-06-29
From Jaden:

(1) A triangle has vertices at (-3,-3) (7,-3) and (-2,5). What is the area of the triangle?

Is there a way of doing this so that you dont have to graph it? If the x axis is horizontal can i say it is the base and the y-axis is horizontal meaning the height. Would I be able to do this...-3 to 7-->9 spaces, -3 to 5-->7 spaces-----9(7)63/2=31.5

(2) A cube has a surface area of 54 square centimeters. What is the volume of the cube in cubic centimeters?

Answered by Stephen La Rocque.
Order of Operations 2006-06-29
From Marcy:
I have been having problems with this skill testing question. I know the rules of operation but I don't understand why they would put it in brackets. Can you help me. I have two answers but I would like to know which one is right. Im having a disagreement with a friend over this matter. Thank you so much

[ (20 + 82 - 6) ÷ 16 ] x 14

Answered by Steve La Rocque and Paul Betts.
Ordre des opérations 2006-04-07
From Chantal:
1435/5x2-364= j'aimerais savoir la reponse et que veux dire la barre /
Answered by Claude Tardif.
BEDMAS 2006-03-21
From Andie:
It's been a long time since I've used bedmas. I'm still confused as to what the answer to this question would be.
30 - (2 x 9) + (15/3)=

Answered by Penny Nom.
BEDMAS 2006-01-31
From Janielle:
What Do All the Letters In BEDMAS Stand for?
Answered by Penny.
BEDMAS 2005-11-24
From Judy:
My name is Judy and I am a grade 6 teacher.
We have just started our lessons on the order of operations and my students have asked me why we have BEDMAS and what is the logic to it.

Is there a reason that that we do math in this particular order?

Who invented this rule or how was it decided on and when?

Answered by Walter Whiteley.
BEDMAS 2005-09-01
From A student:
I am a student and am wondering about the answer to this question.


is the answer 7?

Answered by Harley Weston.
Strategies for teaching operations with positive and negative decimal numbers 2005-02-02
From Erin:
I am wondering if you can suggest any strategies for teaching operations with positive and negative decimal numbers that do not rely on rules that must be memorized?
Answered by Diane Hanson.
Order of operations 2004-11-10
From Andrew:
I'm trying to solve this question, and I can't seem to remember the rules back from my high school days.

(40 x 8 ) / 2 + 55 - 15 =

Can you help me with the answer?

Answered by Harley Weston.
Bedmas 2004-11-09
From Fariha:
i have a single line question and am not sure of the method it would be appreciated if u could send me a method and a solution Q : 1 + 9 / 2 + 5 * 1000

would this be solved by BEDMAS? if not, why?

Answered by Penny Nom.
Bedmas 2004-10-30
From Gina:
I am just curious whether Bedmas would be used in the following question as it is not in the typical Bedmas format.

Multiply 12 x 24
Add 26
Divide by 2
Subtract 7

Would we go about doing it in the sequence it is given or in Bedmas ?

Answered by Penny Nom.
Order of operations 2004-09-04
From Leanne:
6 + 3 - 2 x 3 =
Answered by Claude Tardif.
Combined operations 2004-08-26
From Louise:
Question 2 1/4 x 1/8 / 1 3/4 x 12 4/9 x 3 =
Answered by Penny Nom.
50/5x - y 2004-08-22
From Rick:
Niece has a question that was marked wrong but we are unable to determine how the teacher calculated and arrived at the answer? The problem was as follows:
50 / 5x - y =


Answered by Harley Weston and Leeanne Boehm.
(3x50)+20/5=? 2004-04-03
From A student:
what is the answer to:


Answered by Penny Nom.
BEDMAS 2004-03-20
From Brad:
I am in grade 7. My teacher tells me brackets always first, well i know that but, 5 (-4) x 2

Does the (-4) count as a bracket or is it just telling you not to minus 4 from 5 but to multiply 5 x -4 ? Am i correct?

Answered by Penny Nom.
Order of operations 2004-01-28
From John:

I am trying to find out any information concerning the development of the order of operations. for example, when (why/how) did it become the case that 2 + 3 x 5 =17, rather than 25.

any insight is appreciated. Thank you.

Answered by Penny Nom.
BEDMAS 2004-01-21
From Jessica and her mom:

my mom and I were wondering 2 things.

1. what is the reason for having bedmas.
2. 5+5-4+[6x3-(6+1-3x2) -5+9]

Answered by Penny Nom.
Order of operations 2003-09-07
From Brian:

It has to do with the 4 rules of operations, Parentheses first before operations outside/evaluate all exponential expressions/all multiplication and divisions/then all additions and subtractions.

Who made these rules and when did they make them,,, I know its somewhat of an unorthadox question but I must know. I would really appreciate it.

Answered by Penny Nom.
4-3(m+1)=(-38) 2003-06-25
From Jamie:

I have a problem, like most of your mailers, I do remember BEDMAS but maybe I'm missing the finer points!

It's been a while, he goes


Answered by Penny Nom.
BEDMAS 2003-05-31
From Kristie:

I know bedmas but i forget how to do it.

Answered by Penny Nom.
38 minus 10 plus 12 divided by 4 times 16 2003-04-23
From James:
please help me work this math problem 38 minus 10 plus 12 divided by 4 times 16
Answered by Harley Weston.
Order of operations 2003-02-16
From A student:
How is the order of operation used in everyday life other than in a math class or at school? Also .... Can you give me a list of all the mathematician that are still living that uses the order of operation?
Answered by Claude Tardif.
Order of operations 2003-02-15
From Debbie:
Question: 20-(9+4)x7=?
Possible answer -71 or 49?

Answered by Penny Nom.
BEDMAS 2003-02-09
From Stefanie:
I do remember the rules of BEDMAS, but for some reason this question puzzles me.

6 X 9 - 3 + 44

I started with the Multiplication

54 - 3 + 44

But then I got stuck, do I proceed with adding the 44 and subtracting the 3
or figure out what -3 + 44 is, but then how would that work with 54?

Answered by Penny Nom.
Augmented matrix 2002-12-31
From Michelle:
I am trying to augment a matrix so that i can find the values of the variables a, b, and c. For the life of me i can't find a solution to the matrix: 3 -5 2 ' 22 2 3 -1 ' -9 4 3 3 ' 1 I thank you for your help, Michelle
Answered by Penny Nom.
Number play 2002-09-24
From Julie:
Organize these numbers and the operations so that each equation is correct. Use each coice only once per equation.

36 18 12 6 - + ( ) /

_________________________ = 22

_________________________ = 41

Answered by Claude Tardif.
38-10+12divided by4multiplied by 16 2002-08-30
From Brenda:
my math question is as follows: 38-10+12divided by4multiplied by 16=?
Answered by Penny Nom.
Order of operations 2002-07-18
From Danna:
I would like to know how to solve this type of problem; I already have the answer.

Problem: 2 [5 (4 + 6) - 2] = 96

Also, what do you call this type of problem? Thanks a lot.

Answered by Penny Nom.
8/13*26/27 2002-05-01
From Arias:
Answered by Penny Nom.
An augmented matrix 2002-04-20
From A student:
Hi my math teacher asked us to solve an augmented matrix. I am in twelfth grade and need help. The book we are working on is college algebra. Here it is


Answered by Penny Nom.
What is wrong with these probelms? 2001-02-09
From Cindy:
Hi, I am a planning on becomming a teacher and i am asked to find out what is wrong with these probelms and how i would go about showing a student what is wrong with them!!

Error in patterns:
13/35=1/5; 27/73=2/3; 16/64=1/4

4/5+2/3=6/8; 2/5+3/4=5/9; 7/8+1/3=8/11

2/3*3=6/9; 1/4*6=6/24; 4/5*2=8/10

Answered by Leeanne Boehm and Penny Nom.
Order of operations 2000-11-26
From Margaret Pratt:
My daughter has a math question and I am afraid I am of no help. Can you help? 2x5/2+1-5= She arrives at 8 as the answer and has been told this is incorrect. Any help you can give would be appreciated.
Answered by Penny Nom.
Order of operations 2000-09-19
From Nicole:
the problem is, 4x8-18 divided by 6= do you solve this by doing 4x8=32 then by dividing 18by 6= 3, then subtracting 3 from 32 = 29? If not what is the order of operation?
Answered by Penny Nom.
Eligibility in a contest 2000-03-14
From Ken Rabley:
Hi, hoping you can help. Dispute among co-workers. Tell me, what is the correct answer to the following question:
-1936 + (2406/4812) x (4756 - 3256) + 1250

Seems this is the question for eligibility in a contest...We have come up with various solutions, all which may be correct.

Answered by Penny Nom.
Order of operations 2000-02-27
From Mildred Saulsbery:
Find the value of the expression.
 6(5+1) - 9(1+1) _____________    5(8 - 6) -23 

Answered by Harley Weston.
Order of operations 2000-01-16
From Dorothy:
I was wondering if you could tell me where I can get some info. on how to solve the following problem. I was given the answer but I don't know how it is solved.


Answered by Penny Nom.
Order of operations 1999-10-25
From Garrett:
Answered by Penny Nom.
(-5)^2, -5^2 and -(5)^2 1999-10-13
From Jennifer Brown:
What is the difference between the following problems:

(-5)2, -52 and -(5)2

Our text book (Beginning Algebra, fourth edition, published by McGraw Hill, by Streeter, Huthison and Hoetzle) says the second and third problem are exactly the same. I don't see how that can be. Is there a mathematical rule that explains this?
Answered by Penny Nom.

-8*-(-5a)=15 1999-09-22
From Shelby:

i cannot get this question!! please help me!!
Answered by Harley Weston.

Linear programming and optimization 1999-04-09
From Shams:
What is Linear programming and optimization?
Answered by Jack LeSage and Penny Nom.
Operations Research 1998-10-08
From Lisa Barrett:
What is the history of operations research and the study of linear programming?
Answered by Judi McDonald.
Priority of operations 1996-11-04
From Wallace:
What is the answer to this problem? Let x=-2 and y=3. Evaluate 12x / 2y (if the old division sign is used).
Answered by Chris Fisher.
Ordre des opérations 2006-05-15
From Chantal:
2324/4-153+619= je sais pas comment calculer merci
Answered by Claude Tardif.
Opérations de base 2003-07-05
From Anne-Marie:
Je m'appelle Anne-Marie et je suis enseignante de 5e année à l'école Domaine des copains de Balmoral au Nouveau-Brunswick. Récemment, j'ai participé à un concours intitulé: Budweiser King Pack Nascar Hat Promo. Afin de réclamer le prix, qui est une casquette, je devais répondre à une question réglementaire. Il s'agissait d'une phrase mathématique qui se présentait comme suit:

4 x 26 - 24 / 8 = qui se lit: 4 fois 26 moins 24 divisé
par 8

Answered by Claude Tardif.
Fractions 2003-05-10
From Jacques:
Voici la question qu'il pose: 2 x (1/2+1/4) + 3 + 2 x (1/3-1/4). La reponse est 4 2/3. Pourriez m'expliquer etapes par etapes ce que je dois faire.
Answered by Claude Tardif et Diane Hanson.



Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.



Home Resource Room Home Resource Room Quandaries and Queries Mathematics with a Human Face About Math Central Problem of the Month Math Beyond School Outreach Activities Teacher's Bulletin Board Canadian Mathematical Society University of Regina PIMS