Tap the blue circles to see an explanation.
$$ \begin{aligned}(x+3)(x-1)(x-2)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}(x^2-x+3x-3)(x-2) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}(x^2+2x-3)(x-2) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}x^3-2x^2+2x^2-4x-3x+6 \xlongequal{ } \\[1 em] & \xlongequal{ }x^3 -\cancel{2x^2}+ \cancel{2x^2}-4x-3x+6 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}x^3-7x+6\end{aligned} $$ | |
① | Multiply each term of $ \left( \color{blue}{x+3}\right) $ by each term in $ \left( x-1\right) $. $$ \left( \color{blue}{x+3}\right) \cdot \left( x-1\right) = x^2-x+3x-3 $$ |
② | Combine like terms: $$ x^2 \color{blue}{-x} + \color{blue}{3x} -3 = x^2+ \color{blue}{2x} -3 $$ |
③ | Multiply each term of $ \left( \color{blue}{x^2+2x-3}\right) $ by each term in $ \left( x-2\right) $. $$ \left( \color{blue}{x^2+2x-3}\right) \cdot \left( x-2\right) = x^3 -\cancel{2x^2}+ \cancel{2x^2}-4x-3x+6 $$ |
④ | Combine like terms: $$ x^3 \, \color{blue}{ -\cancel{2x^2}} \,+ \, \color{blue}{ \cancel{2x^2}} \, \color{green}{-4x} \color{green}{-3x} +6 = x^3 \color{green}{-7x} +6 $$ |