Tap the blue circles to see an explanation.
$$ \begin{aligned}(6x-9)(4x+2)(x-3)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}(24x^2+12x-36x-18)(x-3) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}(24x^2-24x-18)(x-3) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}24x^3-72x^2-24x^2+72x-18x+54 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}24x^3-96x^2+54x+54\end{aligned} $$ | |
① | Multiply each term of $ \left( \color{blue}{6x-9}\right) $ by each term in $ \left( 4x+2\right) $. $$ \left( \color{blue}{6x-9}\right) \cdot \left( 4x+2\right) = 24x^2+12x-36x-18 $$ |
② | Combine like terms: $$ 24x^2+ \color{blue}{12x} \color{blue}{-36x} -18 = 24x^2 \color{blue}{-24x} -18 $$ |
③ | Multiply each term of $ \left( \color{blue}{24x^2-24x-18}\right) $ by each term in $ \left( x-3\right) $. $$ \left( \color{blue}{24x^2-24x-18}\right) \cdot \left( x-3\right) = 24x^3-72x^2-24x^2+72x-18x+54 $$ |
④ | Combine like terms: $$ 24x^3 \color{blue}{-72x^2} \color{blue}{-24x^2} + \color{red}{72x} \color{red}{-18x} +54 = 24x^3 \color{blue}{-96x^2} + \color{red}{54x} +54 $$ |