I need help with this. math problem. be smart to answer!?

Question

i dont know what 2 equations to set up.

The length of a certain rectangle is twice its width. If the length is decreased by three centimeters, the area of the resulting rectangle is twelve square centimeters less than the area of the original rectangle. find the original dimenstions of the rectangle.

please help! (: thank you

Answer 1

2w = L, so

A = 2w * w

(2w-3) * w = A - 12

Hope that helps. If you need some more help let me know.

Answer 2

umm if this is part of ur hw or sumthign thts called cheating figure it out on ur own :)

Answer 3

length = width x 2 = 2w

width = w

w( 2w - 3 ) = w( 2w ) - 12

2w^2 - 3w = 2w^2 - 12

-3w = -12

w = 4

answer:

Width = 4

Length = 8

Answer 4

The equations follow the words.

"The length of a certain rectangle is twice its width"

L = 2W (eqn 1)

The area of the original rectangle is LW.  The area of the decreased rectangle is (L-3)W

"If the length is decreased by three centimeters, the area of the resulting rectangle is twelve square centimeters less than the area of the original rectangle."

(L-3)W = LW - 12 (eqn 2)

Now reduce eqn 2 to simpler form, and solve these two equations.

LW - 3W = LW - 12

3W = 12

W = 4

hence L = 2W = 8

Check: Area of origninal = 4 * 8 = 32

Area of reduced rectangle = 4 * 5 = 20, which is 12 less than 32, CHECK!