Answer:
Bacteria, algae and other organisms thrive under warm water conditions this is obviously harmful not just for athletes but the general public in a commercial swimming pool, for competitive pools the water should be no higher than 82°F (28°C), for recreational pools the recommended maximum is 84°F (29°C).
Step-by-step explanation:
Let's simplify step-by-step.<span><span><span>9<span>(<span><span>2x</span>−1</span>)</span></span>−<span>9x</span></span>−<span>18
</span></span>Distribute:<span>=<span><span><span><span><span><span><span>(9)</span><span>(<span>2x</span>)</span></span>+<span><span>(9)</span><span>(<span>−1</span>)</span></span></span>+</span>−<span>9x</span></span>+</span>−18</span></span><span>=<span><span><span><span><span><span><span>18x</span>+</span>−9</span>+</span>−<span>9x</span></span>+</span>−<span>18
</span></span></span>Combine Like Terms:<span>=<span><span><span><span>18x</span>+<span>−9</span></span>+<span>−<span>9x</span></span></span>+<span>−18</span></span></span><span>=<span><span>(<span><span>18x</span>+<span>−<span>9x</span></span></span>)</span>+<span>(<span><span>−9</span>+<span>−18</span></span>)</span></span></span><span>=<span><span>9x</span>+<span>−<span>27
</span></span></span></span>Answer:<span>=<span><span>9x</span>−<span>27</span></span></span>
