Find the dimensions of the rectangle.

Question

The length of a rectangle is 77 centimeters less than four timesfour times its width. Its area is 1515 square centimeters. Find the dimensions of the rectangle. 

Answer 1

A = L * w

 

15 = (4w-7)*w

 

0 = (4w-7)*w - 15

 

0 = 4w^2 - 7w - 15

 

0 = (  4w      +    5)(w    -      3  )

 

4w + 5 = 0  results in negative measures

 

w - 3 = 0 ---> w=3

 

L = 4*3 - 7 = 12 - 7 = 5

 

Length is 5, width is 3