Question
Answer
$$9x^2+6-(3x-5)^2=30x-19$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}9x^2+6-(3x-5)^2& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}9x^2+6-(9x^2-30x+25) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}9x^2+6-9x^2+30x-25 \xlongequal{ } \\[1 em] & \xlongequal{ } \cancel{9x^2}+6 -\cancel{9x^2}+30x-25 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}30x-19\end{aligned} $$ | |
| ① | Find $ \left(3x-5\right)^2 $ using formula. $$ (A - B)^2 = \color{blue}{A^2} - 2 \cdot A \cdot B + \color{red}{B^2} $$where $ A = \color{blue}{ 3x } $ and $ B = \color{red}{ 5 }$. $$ \begin{aligned}\left(3x-5\right)^2 = \color{blue}{\left( 3x \right)^2} -2 \cdot 3x \cdot 5 + \color{red}{5^2} = 9x^2-30x+25\end{aligned} $$ |
| ② | Remove the parentheses by changing the sign of each term within them. $$ - \left( 9x^2-30x+25 \right) = -9x^2+30x-25 $$ |
| ③ | Combine like terms: $$ \, \color{blue}{ \cancel{9x^2}} \,+ \color{green}{6} \, \color{blue}{ -\cancel{9x^2}} \,+30x \color{green}{-25} = 30x \color{green}{-19} $$ |
This page was created using
Simplify polynomials calculator