Geometry- find the length of a rectangle using perimeter and width

Question

A rectangle has perimeter P, length l, and width w. How do you represent l in terms of P and w. 

Answer 1

P = 2 (l+w)

 

P= 2l +2w

 

so 2l = P -2w /2

 

l= P/2 -w

 

 

Answer 2

P = l + w + l + w

 

P = 2l + 2w

 

2l = P- 2w

 

l = (P - 2w)/2