The perimeter of a rectangle is 68 ft. find the dimensions of the rectangle if the ratio of the length to the width is 9 : 8. which of the following would be the best equation to use to solve this problem?

The perimeter of a rectangle is 

P = 2w +2l
P = 68 ft

and given the ratio l/w = 9/8 from this result 8l = 9w so l = (9w)/8

P = 2w +2l

68 = 2w +2((9w)/8)

68 = 2w +9w/4

4*68 = 8w +9w

272 = 17w

w = 272/17

w = 16 

so than we know that w=16 so than the length will be 

l = (9w)/8

l = 9*16/8

l = 9*2

l = 18

so than we know that 

l = 18
w = 16