Two times the width of a certain rectangle exceeds its length by three inches, and eight times its length is twelve more than its perimeter. Find the width of the rectangle.

Perimeter is the sum of all sides of a shape. For a rectangle, it is the sum of the two lengths and two width measurements. We set up the equations as follows:

l = 2w - 3

P = 8l - 12

P = 2w + 2l

8l - 12 = l - 3 + 2l

5l = 9

l = 9/5

9/5 = 2w - 3

w = 12/5