Answer
$$12-2(3x-2)(3x+2)-(2x+5)=-18x^2-2x+15$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}12-2(3x-2)(3x+2)-(2x+5)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}12-(6x-4)(3x+2)-(2x+5) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}12-(18x^2+12x-12x-8)-(2x+5) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}12-(18x^2-8)-(2x+5) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}12-18x^2+8-(2x+5) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle5}{\textcircled {5}} } }}}-18x^2+20-(2x+5) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle6}{\textcircled {6}} } }}}-18x^2+20-2x-5 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle7}{\textcircled {7}} } }}}-18x^2-2x+15\end{aligned} $$ | |
| ① | Multiply $ \color{blue}{2} $ by $ \left( 3x-2\right) $ $$ \color{blue}{2} \cdot \left( 3x-2\right) = 6x-4 $$ |
| ② | Multiply each term of $ \left( \color{blue}{6x-4}\right) $ by each term in $ \left( 3x+2\right) $. $$ \left( \color{blue}{6x-4}\right) \cdot \left( 3x+2\right) = 18x^2+ \cancel{12x} -\cancel{12x}-8 $$ |
| ③ | Combine like terms: $$ 18x^2+ \, \color{blue}{ \cancel{12x}} \, \, \color{blue}{ -\cancel{12x}} \,-8 = 18x^2-8 $$ |
| ④ | Remove the parentheses by changing the sign of each term within them. $$ - \left( 18x^2-8 \right) = -18x^2+8 $$ |
| ⑤ | Combine like terms: $$ \color{blue}{12} -18x^2+ \color{blue}{8} = -18x^2+ \color{blue}{20} $$ |
| ⑥ | Remove the parentheses by changing the sign of each term within them. $$ - \left( 2x+5 \right) = -2x-5 $$ |
| ⑦ | Combine like terms: $$ -18x^2+ \color{blue}{20} -2x \color{blue}{-5} = -18x^2-2x+ \color{blue}{15} $$ |
This page was created using
Simplify polynomials calculator