<p>Instead of generating an algebraic expression, I simply plugged in arbitrary values. It seems as though ETS wants me to solve the problem, by way of the former method. Does it matter, really?</p>
<p>plugging in numbers until you get the right answer may have worked fine in this problem but in other problems that may not be as easy or would take much longer, it is much easier and more time efficient to do it algebraically</p>
<p>On these sorts of questions yes it’s more efficient imo to just make up values. It’s much less error prone and since you’re now dealing with concrete numbers you can check to make sure the answer is logical, which isn’t as possible with abstract variables.</p>
<p>That is half-way to one of the best approaches. Use plug numbers, but not … random numbers. When picking “arbitrary” numbers, you should always have the final answer in mind, and not relying on luck or wild speculation. </p>
<p>In this case, since the answers contains “percents” you should start with a … square of 10 x 10. The original area will thus be 100. From there, all you need is 8 x 12 = 96 to find the correct answer of 4 percent decrease. </p>
<p>This problem is solved in 5 to 15 seconds.</p>
<p>PS Although it is NOT needed, a “purist” might have stuck to a rectangle. In that case, the values might have been 5 by 20 (still need that 100) and the answer them be 6 x 16 = 96 or 4 x 24 = 96. Not a big difference … but 10 x 10 is simpler.</p>
