Tap the blue circles to see an explanation.
| $$ \begin{aligned}(x+2)(x-5)(x-2)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}(x^2-5x+2x-10)(x-2) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}(x^2-3x-10)(x-2) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}x^3-2x^2-3x^2+6x-10x+20 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}x^3-5x^2-4x+20\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{x+2}\right) $ by each term in $ \left( x-5\right) $. $$ \left( \color{blue}{x+2}\right) \cdot \left( x-5\right) = x^2-5x+2x-10 $$ |
| ② | Combine like terms: $$ x^2 \color{blue}{-5x} + \color{blue}{2x} -10 = x^2 \color{blue}{-3x} -10 $$ |
| ③ | Multiply each term of $ \left( \color{blue}{x^2-3x-10}\right) $ by each term in $ \left( x-2\right) $. $$ \left( \color{blue}{x^2-3x-10}\right) \cdot \left( x-2\right) = x^3-2x^2-3x^2+6x-10x+20 $$ |
| ④ | Combine like terms: $$ x^3 \color{blue}{-2x^2} \color{blue}{-3x^2} + \color{red}{6x} \color{red}{-10x} +20 = x^3 \color{blue}{-5x^2} \color{red}{-4x} +20 $$ |