Question

If a rectangle has a perimeter of 70, a length of x and a width of x - 9, find the value of the length of the rectangle.

Answer 1

The perimeter of a rectangle that is 70 can be put into an equation like this:
2l + 2w = 70

The information given for us is this:
length = x
width = x - 9

Plug in the values for length and width:
2(x) + 2(x - 9) = 70
Multiply through the parenthesis:
2x + 2x - 18 = 70
Combine like terms:
4x = 88
Divide by 4 on both sides:
x = 22

The length of the rectangle is 22.