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