area of yard minus the area of the pool

Question

Tony is installing a rectangular pool in the backyard. The pool needs to have a length of 10 feet more than the width. The backyard is a square shape with each of the sides measuring 5 feet more than 3 times the width of the pool. Write an expression for the area surrounding the pool after the pool is installed.

Answer 1

A_backyard = (3w + 5)²

A_pool = w(w + 10)

A_surround = (3w + 5)² - w(w + 10)

 

Can you solve for w and answer?