A rectangular pool that's $10~\text{m}$ by $4~\text{m}$ is surrounded by a deck of uniform width the combined area of the deck and the pool is $135~\text{m}^2$. Whats the deck width?
So what I've done so far is I have determined that the area of the pool is $40~\text{m}^2$, and the area of the deck is $95~\text{m}^2$, and the perimeter of the pool is $28~\text{m}$, but I'm not sure what equation I'm supposed to use to determine the length and width of the deck.
I'm new to this site, so if I'm missing something or I'm using the site wrongly, I would appreciate it if you let me know.