Question

The width of a swimming pool is 12 feet less than the pool's length. The area of the pool is 540 square feet. What are the dimensions of the pool?

Answer 1

let
x----------> the width of the pool
y---------> the length of the pool

we know that
x=y-12-----------> equation 1
540 ft²=x*y ----------> equation 2

substitute 1 in 2

540=[y-12]*y-----> y²-12y-540=0

using a graph tool-----> to resolve the second order equation
see the attached figure

the solution is
y=30 ft
x=y-12------> x=30-12------> x=18 ft

the answer is
the width of the pool is 18 ft
the length of the pool is 30 ft