A rectangular swimming pool is 7 meters longer then it is wide. It is surrounded by a concrete walkway 1.5 meters wide. The area of the walkway is 120 meters squared. What are the dimensions of the pool?

Answer 1

width of pool ---> x
length of pool --> x+7
area of pool = x(x+7)

width of whole pool area = x+3
length of whole pool area = x+7+3 = x+10

area of pool area = (x+3)(x+10)

area of concrete walkway = area of whole thing - area of pool
solve
120 = (x+3)(x+10) - x(x+7)
etc.

(you should get x = 15)