430fa576-7ec6-4a43-af17-b231acf42b1e.html

<h4>Cool Down Activity</h4>
<div class="os-raise-ib-cta" data-button-text="Solution" data-fire-event="Reveal1" data-schema-version="1.0">
  <div class="os-raise-ib-cta-content">
    <p>Here is someone's solution to the equation \(3x^2&minus;4x=20\).</p>
    <p><strong>Step 1</strong> - \(3x^2&minus;4x=20\)</p>
    <p><strong>Step 2</strong> - \(a=3\), \(b=-4\), \(c=20\)</p>
    <p><strong>Step 3</strong> - \(x=\frac{-b \pm \sqrt{b^2- 4ac}}{2a}\)</p>
    <p><strong>Step 4</strong> - \(x=\frac{-4 \pm \sqrt{(-4)^2- (4)(3)(20)}}{2(3)}\)</p>
    <p><strong>Step 5</strong> - \(x=\frac{-4 \pm \sqrt{-16-240}}{6}\)</p>
    <p><strong>Step 6</strong> - \(x=\frac{-4 \pm \sqrt{-256}}{6}\)</p>
    <p>No Solutions</p>
    <p>Identify as many errors as you can and briefly explain each error.</p>
  </div>
  <div class="os-raise-ib-cta-prompt">
    <p>Write down your answer, then select the <strong>solution</strong> button to compare your work.</p>
  </div>
</div>
<div class="os-raise-ib-content" data-schema-version="1.0" data-wait-for-event="Reveal1">
  <p>Compare your Answer:</p>
  <ul class="os-raise-noindent">
    <li> \(b\) is -4, so in Step 4, the value \(-b\) should be -(-4), which is 4. </li>
    <li> In Step 1, the equation should be rewritten as \(ax^2+bx+c=0\), so the constant term \(c\) is -20, not 20. So, in Step 4, the last part of the numerator should be \(\sqrt{(-4)^2-4(3)(-20)}\). </li>
    <li> In Step 4, \((-4)^2\) should be 16. Squaring a negative number gives a positive number. </li>
    <li> If the earlier issues were fixed, then the values under the square root symbol would be \(16+240\) or 256. </li>
  </ul>
</div>