<p><span style="font-size:22px"><a target="_blank" href="https://www.prepswift.com/quizzes/quiz/prepswift-variables" target="_blank">Variables Exercise</a></span></p><p><span style="color:#2ecc71;">Variables</span> represent unknown values in mathematical expressions. Think of them as the "mystery guests" in a math party.</p>
<p>Some examples:</p>
<ul>
<li>$x + 5 = 13$: Here, $x$ is the variable, or the "mystery guest," that needs to be identified.</li>
<li>$y \times 4 = 24$: In this case, $y$ is the variable, playing the role of the undercover agent.</li>
</ul>
<p>According to ETS (the word of Zeus):</p>
<blockquote>
<p>Variables are letters that represent an unknown quantity.</p>
</blockquote>
<p>In the world of formulas, some variables are like celebrities making frequent appearances:</p>
<ul>
<li>$r$ is often seen representing "radius" or "rate" (r is really versatile).</li>
<li>$w$, $r$, and $t$ are the stars of "work," "rate," and "time" (they're practically in every math blockbuster).</li>
</ul>
<p>However, not all letters get to join the variable VIP club. Letters like $e$, $i$, $o$, $a$, $b$, and $c$ are usually avoided because they tend to represent other fixed values. These are not hard and fast rules, though—just more like dress code suggestions at a fancy party.</p>
<p>Variables can represent one or multiple values, depending on the equation. Here's how our mystery guests can behave:</p>
<ul>
<li>$x+4=11$: In this simple case, $x$ is just one value—$7$ (not much of a mystery here).</li>
<li>$x^2 = 49$: Now, $x$ is feeling adventurous and can be two values, $7$ or $-7$ (it has a twin!).</li>
<li>$(x-2)(x)(x+2) = 0$: Here, $x$ is really showing off with three possible values—$2$, $0$, or $-2$ (a triple threat!).</li>
<li>$x+y=7$: For $x$ and $y$, the possibilities are endless as long as they add up to $7$ (they're the life of the infinite possibilities party).</li>
</ul>
<p>So, next time you're working with variables, just think of them as the elusive mystery guests at the grand math gala, waiting to be revealed!</p>