Christion and Jessica want to build a pool in their backyard. However they also have dogs so they do not want the pool to take up all of the backyard. Christion is wondering how much room the dogs will have to run while jessica is concerned about the size of the pool. They know that the area of their rectangular yard is represented by the equation f(x)-3x^2-14x-5. The area of the pool can be represented by the equation f(x)=(x-4)(2x+7).

What is the area of the grassy space where the dogs can run?

Can someone please help me with the steps of how to solve this :\

area grassy space=area yard-area pool

= 3x^2 -14x-5 -(x-4)(2x+7).
= 3x^2 -14x-5-(2x^2+7x-8x-28)
=x^2 -13x+23 check all that