Answer
$$7x^2-(2x+6)^2=3x^2-24x-36$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}7x^2-(2x+6)^2& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}7x^2-(4x^2+24x+36) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}7x^2-4x^2-24x-36 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}3x^2-24x-36\end{aligned} $$ | |
| ① | Find $ \left(2x+6\right)^2 $ using formula. $$ (A + B)^2 = \color{blue}{A^2} + 2 \cdot A \cdot B + \color{red}{B^2} $$where $ A = \color{blue}{ 2x } $ and $ B = \color{red}{ 6 }$. $$ \begin{aligned}\left(2x+6\right)^2 = \color{blue}{\left( 2x \right)^2} +2 \cdot 2x \cdot 6 + \color{red}{6^2} = 4x^2+24x+36\end{aligned} $$ |
| ② | Remove the parentheses by changing the sign of each term within them. $$ - \left( 4x^2+24x+36 \right) = -4x^2-24x-36 $$ |
| ③ | Combine like terms: $$ \color{blue}{7x^2} \color{blue}{-4x^2} -24x-36 = \color{blue}{3x^2} -24x-36 $$ |
This page was created using
Simplify polynomials calculator