Linear Equations on the Plane

<p><span style="font-size:22px"><a target="_blank" href="https://www.prepswift.com/quizzes/quiz/prepswift-linear-equations-on-the-plane">Linear Equations on the Plane Exercise</a></span></p><p>A linear equation is a first-degree equation involving one or more variables or constants (revisit the algebra section if this sounds like gibberish). On the GRE, <span style="color:#27ae60;">Linear Equations on the Plane</span> will consist of&nbsp;<strong><u>at most</u></strong>&nbsp;two variables: $x$ and $y$. However, it&#39;s also possible to have a linear equation consisting of only one variable, say $x = 5$ or $y=7$.</p> <p><strong><span style="color:#8e44ad;">One-variable equations</span></strong>: Will either be a horizontal line ($y = constant$) or a vertical line ($x=constant$).</p> <ul> <li>Wait, why is $y=4$ a <em>horizontal</em> line? <ul> <li>Because every point on that horizontal line is four points above the $x$-axis.</li> </ul> </li> <li>Wait, why is $x=2$ a <em>vertical</em> line? <ul> <li>Because every point on that line is two points to the right of the $y$-axis.</li> </ul> </li> </ul> <p><strong><span style="color:#8e44ad;">Two-variable equations</span></strong>: Will appear as a &quot;slanted,&quot; or &quot;sloped,&quot; line on the $xy$-coordinate plane.</p> <center><svg height="255.16429138183594" style=" width:661.8285522460938px; height:255.16429138183594px; background: #FFF; fill: none; " width="661.8285522460938" x="0" xmlns="http://www.w3.org/2000/svg" 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