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Explaining the factoring for the difference of cubes |
2008-01-16 |
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From Bill:
A student asked me where did the "difference of cubes" and "sum of cubes" come from. I did not have an answer for her. She is very bright and understands how they work but wanted to know where they derived from. Any help you can offer would be great. Thanks
Answered by Stephen La Rocque. |
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The distance back to school |
2008-01-16 |
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From priya:
a boy starts travelling from his house to his school. He travels 1 km east and then
2km north and then 1 km East and 1km North and then 1 km east and then 1 km North.
find out the shortest distance for him to reach his shool?
Answered by Harley Weston. |
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A 16 sided lot |
2008-01-16 |
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From R:
I am having a land of 16 irregular sides i know all the length of the sides how to calculate the
area of the land
Answered by Harley Weston. |
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How many rolls of stock do I need to buy? |
2008-01-16 |
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From Dan:
How many rolls of stock do I need to buy?
Given:
The rolls are 40" wide, 20" roll o.d., 4" core o.d., gauge is 0.008"
I need to cut these master rolls in 6" strips (4" of waste per master roll)
and I need 1,270,500 linear feet of this strip.
Answered by Stephen La Rocque. |
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8 workers dug 3/8 of a tunnel in 10 days |
2008-01-15 |
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From Marc:
8 workers dug 3/8 of a tunnel in 10 days. If the need to finish the remaining 5/8 of the tunnel in 3 1/3 days, how many more workers must they hire?
Answered by Penny Nom. |
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Pie graphs |
2008-01-15 |
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From amarilis:
explain why circle graphs are called pie graph or pie charts
Answered by Stephen La Rocque. |
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Balancing on a fulcrum (net torque and equilbrium) |
2008-01-15 |
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From Eric:
If I have a 4" bar that has no weight value with a 275lb. weight on one side
and a 125lb. weight on the other side what would be the folcrum point? Please
keep the answer very simple. Also is there a fixed equation to figure folcrum points?
Is there an equation for if the 4" bar had a weight value?
Answered by Stephen La Rocque. |
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Maximum volume of a box |
2008-01-15 |
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From Rajesh:
A square piece of a cardboard of sides ten inches has four equal peices are removed at the corners, then the sides are turned up to form an open box. What is the maximum volume such a box can have?
Answered by Stephen La Rocque. |
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Percentage and units |
2008-01-15 |
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From Kenneth:
Hello:
If the sales tax on merchandise sold in stores is 6%. The item is
multiplied by the sales tax of 6%. For example, the sales tax on
pencils worth $1.00 is 6% X $1.00 is $0.06 or 6 cents plus $1.00 for
a total of $1.06.
1. If the tax is 6%/$1.00, why doesn't the dollar sign as a unit cancel
after the multiplication?
Isn't it 6%/$1.00 X $1.00 or whatever the dollar amount is?
The dollar signs should cancel, but they do not.
2. If percentages are unitless, is there a reason?
Answered by Harley Weston. |
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Two rectangles |
2008-01-15 |
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From Paul:
If the smaller dimension of a rectangle is increased by 3 feet and the larger
dimension by 5 feet, one dimension becomes 3/5 of the other,
and the area is increased by 135 square feet. find the original dimensions
Answered by Penny Nom. |
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What do I need on the exam to get an average of 75%? |
2008-01-15 |
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From Alyssa:
Hi there,
I was wondering how i could calculate the mark i need on my upcoming exam in order to increase my final grade. If i currently have a 65% in a class and my final exam is worth 20% what would i need to get on my exam to increase at least 10%
thanks :)
Answered by Penny Nom. |
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Range of a Function |
2008-01-15 |
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From Amanda:
I'm studying for the mid-term and I can't seem to grasp this one question on my review sheet. Can you help me?
Find the range of a function y = 32 + 5x where 0 < x < 8 and x is an integer.
Answered by Penny Nom. |
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Constructing a pool |
2008-01-15 |
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From Scott:
what it the cubic yards needed for this pool.
It is 14ft. X 28ft. and 6 inches thick. It is 3.5ft. deep on the shallow end and 6ft. deep at the deep end.
Answered by Stephen La Rocque. |
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How many bags of cement will I need? |
2008-01-15 |
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From James:
I want to extend my front porshe more to the left atleast 14' 1" length wise and 5' 1" width wise with 4" thickness. Now i already decimalized in feet those inches, resulting with 14.08 length and 5.08width and 0.33 of thickness. I then Get my square feet of 71.53. And go on to cubic feet getting a 23.60 in cubic feet. Now i want to convert to cubic yards so i then divide 23.60 into 27 and get 0.87. Now my question is how would i use this to go and buy the necessary bags of cement knowing that a 94 lb. bag of cement is 1 cubic foot of bulk material. To fill 4 inch of thickness and 14' of length and 5 of width?
Answered by Stephen La Rocque. |
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2 divided by x plus 1 is equal to 3 |
2008-01-14 |
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From chilly:
with x being the subject of the formula, what is the answer of 2 divided by x plus 1 is equal to 3?
Answered by Penny Nom. |
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