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Questions: Algebra BusinessCalculus
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Factor \(\displaystyle 8 x^{3} + 72 x^{2} - 5 x - 45\).
Grouping the first two terms and factoring out their GCF, \(\displaystyle 8 x^{2}\), gives \(\displaystyle 8 x^{2}(x + 9)\). Grouping the last two terms and factoring out their GCF, \(\displaystyle -5\), gives \(\displaystyle -5(x + 9)\). The polynomial now has a common binomial factor of \(\displaystyle x + 9\). This gives \(\displaystyle 8 x^{2} \left(x + 9\right) -5 \cdot \left(x + 9\right) = \left(x + 9\right) \left(8 x^{2} - 5\right)\).
\begin{question}Factor $8 x^{3} + 72 x^{2} - 5 x - 45$.
\soln{9cm}{Grouping the first two terms and factoring out their GCF, $8 x^{2}$, gives $8 x^{2}(x + 9)$. Grouping the last two terms and factoring out their GCF, $-5$, gives $-5(x + 9)$. The polynomial now has a common binomial factor of $x + 9$. This gives $8 x^{2} \left(x + 9\right) -5 \cdot \left(x + 9\right) = \left(x + 9\right) \left(8 x^{2} - 5\right)$. }
\end{question}
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\begin{document}\begin{question}(10pts) The question goes here!
\soln{9cm}{The solution goes here.}
\end{question}\end{document}<p> <p>Factor <img class="equation_image" title=" \displaystyle 8 x^{3} + 72 x^{2} - 5 x - 45 " src="/equation_images/%20%5Cdisplaystyle%208%20x%5E%7B3%7D%20%2B%2072%20x%5E%7B2%7D%20-%205%20x%20-%2045%20" alt="LaTeX: \displaystyle 8 x^{3} + 72 x^{2} - 5 x - 45 " data-equation-content=" \displaystyle 8 x^{3} + 72 x^{2} - 5 x - 45 " /> . </p> </p><p> <p>Grouping the first two terms and factoring out their GCF, <img class="equation_image" title=" \displaystyle 8 x^{2} " src="/equation_images/%20%5Cdisplaystyle%208%20x%5E%7B2%7D%20" alt="LaTeX: \displaystyle 8 x^{2} " data-equation-content=" \displaystyle 8 x^{2} " /> , gives <img class="equation_image" title=" \displaystyle 8 x^{2}(x + 9) " src="/equation_images/%20%5Cdisplaystyle%208%20x%5E%7B2%7D%28x%20%2B%209%29%20" alt="LaTeX: \displaystyle 8 x^{2}(x + 9) " data-equation-content=" \displaystyle 8 x^{2}(x + 9) " /> . Grouping the last two terms and factoring out their GCF, <img class="equation_image" title=" \displaystyle -5 " src="/equation_images/%20%5Cdisplaystyle%20-5%20" alt="LaTeX: \displaystyle -5 " data-equation-content=" \displaystyle -5 " /> , gives <img class="equation_image" title=" \displaystyle -5(x + 9) " src="/equation_images/%20%5Cdisplaystyle%20-5%28x%20%2B%209%29%20" alt="LaTeX: \displaystyle -5(x + 9) " data-equation-content=" \displaystyle -5(x + 9) " /> . The polynomial now has a common binomial factor of <img class="equation_image" title=" \displaystyle x + 9 " src="/equation_images/%20%5Cdisplaystyle%20x%20%2B%209%20" alt="LaTeX: \displaystyle x + 9 " data-equation-content=" \displaystyle x + 9 " /> . This gives <img class="equation_image" title=" \displaystyle 8 x^{2} \left(x + 9\right) -5 \cdot \left(x + 9\right) = \left(x + 9\right) \left(8 x^{2} - 5\right) " src="/equation_images/%20%5Cdisplaystyle%208%20x%5E%7B2%7D%20%5Cleft%28x%20%2B%209%5Cright%29%20-5%20%5Ccdot%20%5Cleft%28x%20%2B%209%5Cright%29%20%3D%20%5Cleft%28x%20%2B%209%5Cright%29%20%5Cleft%288%20x%5E%7B2%7D%20-%205%5Cright%29%20" alt="LaTeX: \displaystyle 8 x^{2} \left(x + 9\right) -5 \cdot \left(x + 9\right) = \left(x + 9\right) \left(8 x^{2} - 5\right) " data-equation-content=" \displaystyle 8 x^{2} \left(x + 9\right) -5 \cdot \left(x + 9\right) = \left(x + 9\right) \left(8 x^{2} - 5\right) " /> . </p> </p>