Tap the blue circles to see an explanation.
| $$ \begin{aligned}(x-3)^2(x^2-8x+13)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}(x^2-6x+9)(x^2-8x+13) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}x^4-14x^3+70x^2-150x+117\end{aligned} $$ | |
| ① | Find $ \left(x-3\right)^2 $ using formula. $$ (A - B)^2 = \color{blue}{A^2} - 2 \cdot A \cdot B + \color{red}{B^2} $$where $ A = \color{blue}{ x } $ and $ B = \color{red}{ 3 }$. $$ \begin{aligned}\left(x-3\right)^2 = \color{blue}{x^2} -2 \cdot x \cdot 3 + \color{red}{3^2} = x^2-6x+9\end{aligned} $$ |
| ② | Multiply each term of $ \left( \color{blue}{x^2-6x+9}\right) $ by each term in $ \left( x^2-8x+13\right) $. $$ \left( \color{blue}{x^2-6x+9}\right) \cdot \left( x^2-8x+13\right) = x^4-8x^3+13x^2-6x^3+48x^2-78x+9x^2-72x+117 $$ |
| ③ | Combine like terms: $$ x^4 \color{blue}{-8x^3} + \color{red}{13x^2} \color{blue}{-6x^3} + \color{green}{48x^2} \color{orange}{-78x} + \color{green}{9x^2} \color{orange}{-72x} +117 = \\ = x^4 \color{blue}{-14x^3} + \color{green}{70x^2} \color{orange}{-150x} +117 $$ |