85af0cf7-7025-4e16-9dce-b758af92b6a0.html

<h4>Cool Down Activity</h4>
<p>Here is the <span class="os-raise-ib-tooltip" data-schema-version="1.0" data-store="glossary-tooltip">quadratic formula</span>:</p>
<p>\(x=\frac{-b \pm \sqrt{b^2- 4ac}}{2a}\)</p>
<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>Use the formula to solve the equation \(x^2+9x+8=0\).</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>
  <p>The solutions are -8 and -1.</p>
  <p>Apply the quadratic formula for \(a=1\), \(b=9\), \(c=8\):</p>
  <p>\(x=\frac{-9 \pm \sqrt{(9)^2- 4(1)(8)}}{2(1)}=\frac{-9 \pm \sqrt{49}}{2}\), which means</p>
  <p>\(x=\frac{-9-7}{2}=-8\) and \(x=\frac{-9+7}{2}=-1\).</p>
</div>