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Solving four simultaneous equations (system of four linear equations) |
2007-10-07 |
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From Johan:
I need some help in solving this question
x + 2y - 3z + 4w = 12
2x + 2y - 2z + 3w = 10
0 + y + z + 0 = -1
x - y + z - 2w = -4
Answered by Stephen La Rocque. |
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Direct variation |
2007-10-07 |
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From Kimberly:
If y is directly proportional to the square of x,
and x=2 when y=12, then what is the value of y when x=3?
Answered by Penny Nom. |
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Problems solved using quadratic equations |
2007-10-07 |
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From Lisa:
a. Two positive numbers differ by 5. Their product is 234. What are the two numbers?
b. The sum of two numbers is 12. Their product is 30. What are the two numbers?
c.Two numbers differ by 5. Their squares differ by 55. What are the two numbers?
d. The sum of two numbers is 15. Their product is 56. By forming an equation, find the two numbers.
Answered by Penny Nom. |
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2 aces and 3 kings |
2007-10-05 |
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From Becky:
How many 5-card poker hands consisting of 2 aces and 3 kings are possible with an ordinary 52-card deck?
Answered by Penny Nom. |
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How long was she be raking leaves? |
2007-10-05 |
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From Skylar:
A family is raking leaves. Betsy fills 3 bags to every 2 bags the Meri fill. After a while, Jim joins them. He fills 3 bags to every 2 bags that Betsy fills, but he only works half as long. When finished, they have completely filled 58 bags. If Meri takes 6 minutes to fill one bag, how long was she raking leaves?
Answered by Chris Langdon. |
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Roof trusses |
2007-10-05 |
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From Mary:
I need to know how algebra is used in making or designing of roof trusses for a house. I have to present a poster in class showing how algebra is used in daily jobs. My dad works at a truss company.
Answered by Chris Langdon. |
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Number of real solutions |
2007-10-05 |
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From Sujith:
The no of real solutions of the equations 1+x+x^2+x^3 = x^4+x^5 is ?
Answered by Harley Weston. |
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Solve for K |
2007-10-05 |
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From Ben:
Solve the formula for K
C=30d+0.10k
Answered by Stephen La Rocque. |
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Triangle perimeter and area |
2007-10-05 |
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From divakar:
The sides of the triangle are integers. The perimeter is 8. What is the area?
Answered by Stephen La Rocque. |
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Solving arithmetic problems in the right order (BEDMAS) |
2007-10-05 |
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From Kim:
3+4x2-(10 divided by 5)= what?
Answered by Penny Nom. |
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Find the equation of a line given two points |
2007-10-05 |
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From Tiffany:
The equation for the line through the points (11,2) and (18,12) can be written in the form Ax+By=C.
Find A and B.
Answered by Victoria West. |
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Maximizing profits II |
2007-10-05 |
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From a student:
Suppose there are three firms with the same demand function. The function is Q=1000-40P. Each firm also a a cost function.
Firm 1: 4000+5Q,
Firm 2: 3000+5Q,
Firm 3: 3000+7Q.
What price should each firm charge if it wants to maximize profits.
Answered by Harley Weston. |
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Maximizing profit |
2007-10-05 |
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From a student:
Use the following equation to demonstrate how a firm that produces at MR=MC can also maximize its total profit. The equations to use are
P=170-5Q
TC=40+50Q+5Q^2
Answered by Harley Weston. |
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Show that there is no five-digit number which |
2007-10-04 |
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From Greg:
show that there is no five-digit number which uses each of the digits 1,2,3,4,5 such that the numbers formed
by the first digit is divisible by 1,
by the first two digits is divisible by 2
by the first three digits is divisible by 3,
by the first four digits is divisible by 4,
by the first five digits is divisible by 5
Answered by Stephen La Rocque, Claude Tradif and Victoria West. |
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Equation of a tangent line to a function |
2007-10-04 |
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From Princess:
If f ' (x) = 3x^2 +1, find the equation of
the tangent line to f(x) = x^3 + x at x= -1.
Answered by Stephen La Rocque. |
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