John M. answered • 10/28/14

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Analytical assistance -- Writing, Math, and more

Todd, the key is to translate the sentences into equations.

Let's define L=Length of the rectangle and W=Width of the rectangle

The word "is" tells you where the equals sign is.

Your first sentence translates:

(a rectangles length) [is] 8 cm more than 3 times its {width}.

L = 8cm more than 3 times W

"times" usually means multiplication and "more than" usually means to add, so

L = 8cm more than 3 times W

L = 8 + 3xW or L=8+3W, which is the first equation.

The second sentence is

if the perimeter is 128 cm

The perimeter is the distance around the figure and for a rectangle, starting in the lower left corner, you go up the width (+1W), across the length to the right (+1L), down the width (+1W) and then back left across the length (+1L) or 1W+1L+1W+1L=2W+2L

So the second equation is the perimeter = 2W+2L=128

L=8+3W

2W+2L=128

With these two equations and two unknowns (L & W), there is a unique solution, which I leave for you. I hope this helps.