Tap the blue circles to see an explanation.
| $$ \begin{aligned}(2x+3)(x-5)(x-2)(x+1)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}(2x^2-10x+3x-15)(x-2)(x+1) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}(2x^2-7x-15)(x-2)(x+1) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}(2x^3-4x^2-7x^2+14x-15x+30)(x+1) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}(2x^3-11x^2-x+30)(x+1) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle5}{\textcircled {5}} \htmlClass{explanationCircle explanationCircle6}{\textcircled {6}} } }}}2x^4-9x^3-12x^2+29x+30\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{2x+3}\right) $ by each term in $ \left( x-5\right) $. $$ \left( \color{blue}{2x+3}\right) \cdot \left( x-5\right) = 2x^2-10x+3x-15 $$ |
| ② | Combine like terms: $$ 2x^2 \color{blue}{-10x} + \color{blue}{3x} -15 = 2x^2 \color{blue}{-7x} -15 $$ |
| ③ | Multiply each term of $ \left( \color{blue}{2x^2-7x-15}\right) $ by each term in $ \left( x-2\right) $. $$ \left( \color{blue}{2x^2-7x-15}\right) \cdot \left( x-2\right) = 2x^3-4x^2-7x^2+14x-15x+30 $$ |
| ④ | Combine like terms: $$ 2x^3 \color{blue}{-4x^2} \color{blue}{-7x^2} + \color{red}{14x} \color{red}{-15x} +30 = 2x^3 \color{blue}{-11x^2} \color{red}{-x} +30 $$ |
| ⑤ | Multiply each term of $ \left( \color{blue}{2x^3-11x^2-x+30}\right) $ by each term in $ \left( x+1\right) $. $$ \left( \color{blue}{2x^3-11x^2-x+30}\right) \cdot \left( x+1\right) = 2x^4+2x^3-11x^3-11x^2-x^2-x+30x+30 $$ |
| ⑥ | Combine like terms: $$ 2x^4+ \color{blue}{2x^3} \color{blue}{-11x^3} \color{red}{-11x^2} \color{red}{-x^2} \color{green}{-x} + \color{green}{30x} +30 = 2x^4 \color{blue}{-9x^3} \color{red}{-12x^2} + \color{green}{29x} +30 $$ |