[rarequeen917]

Is this correct


The width of a rectangle is 8 feet less than the length. If the area is 20 square feet, find the length and the width.
Let w = width, then w+8 = length

Area = 20
L * W = 20
(w+8)*w = 20
w^2 +8w = 20 Set equal to zero.
w^2 + 8w - 20 = 0 Factor -->
(w+10)(w-2) = 0 Set each factor equal to zero -->
w + 10 = 0 --> w = -10 Discard because lengths must be positive.

w - 2 = 0 --> w = 2

[BlackVY]

Yup... that is right... and you can do it the other way too... but they are both right. The check you be to say if the width is 2, then the length is (8+2) which is 10, and 10*2=20, so you are right.

If you wanted to find the length out:

Length = x
Width = x-8

x(x-8) = 20
x^2-8x-20= 0
(x-10)(x+2) = 0

So the length would be 10, which is the same number you got from your calculation. Good work :)