need help with this problem please

Question

A community is developing plans for a pool and hot tub. The community plans to form a swim team, so the pool must be built to certain dimensions. Answer the questions to identify possible dimensions of the deck around the pool and hot tub.The dimensions of the pool are to be 25 yards by 9 yards. The deck will be the same width on all sides of the pool. Including the deck, the total pool area has a length of (x + 25) yards, and a width of (x + 9) yards.
1. Write an equation representing the total area of the pool and the pool deck. Use y to represent the total area.

Answer 1

You have a rectangle around a rectangle.  Since you have

the pool plus deck as having length = (x+25) and width = (x+9)

then x is twice the width of the deck.

 

However, the equation for the total area of pool and deck is

still area = length*width

 

y = (x+25)(x+9)

y = x² + 9x + 25x + 225

y = x² + 34x + 225  where x represents twice the width of the deck