the length of a rectangle is three centimeters less than twice its width. If the perimeter of the rectangle is 18 centimeers, find its dimensions

Question

what is the dimensions of the rectangle?

Answer 1

Need two equations:

 

l - 3 = w, l = w +3

 

P = 2w + 2l = 18

 

Substitute:

 

P = 2w + 2l = 18

 

P = 2w + 2(w + 3) = 18

 

Solve for w:

 

2w + 2w + 6 = 18

 

4w + 6 = 18

 

4w + 12

 

w = 3

 

Can you solve for l???