<span>%Antifreeze=<span><span>V<span>Antifreeze</span></span><span>V<span>Fluid</span></span></span></span>
<span><span>V<span>Fluid</span></span>=<span><span>V<span>Antifreeze</span></span><span>%Antifreeze</span></span></span>
<span><span>V<span>Antifreeze</span></span>=<span>V<span>fluid</span></span>∗%Antifreeze</span>
I want to find the amount of antifreeze in a 15 quart solution with 30% antifreeze
<span><span>V<span>Antifreeze</span></span>=15∗0.30</span> =18/4 quarts of antifreeze
Similarly, I want to find the amount of antifreeze in a 15 quart solution with 35% antifreeze first.
<span><span>V<span>Antifreeze</span></span>=15∗0.35</span> = 21/4 quarts of antifreeze
<span>the difference between 21/4 and 18/4 is 3/4 quarts, which is the amount of pure antifreeze I've added in.
</span><span>
SO the V_fluid I replaced with 3/4 quarts of antifreeze is (3/4)/ 0.35</span>
This seems to look like a factoring question. When factoring, one must know that the second number is the sum of the two values multiplied by x, and the third number is what happens when one multiplies those two numbers. Using these definitions, one can conclude that the correct answer is (x-8)(x+3)