Hi,The answer to your question is down belowThe width measures 10 feet.
Let the length be x and the width be <span>x−10</span>.
Since the pool is rectangular:
<span>A=L×W</span>
<span>200=x<span>(x−10)</span></span>
<span>200=<span>x2</span>−10x</span>
<span>0=<span>x2</span>−10x−200</span>
<span>0=<span>(x−20)</span><span>(x+10)</span></span>
<span>x=20and−10</span>
A negative answer is not possible, so the width of the pool is <span><span>(20−10)</span>=10</span> feet.
Hoped I Helped