Tap the blue circles to see an explanation.
$$ \begin{aligned}3(x-4)^2+2(x-4)+3& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}3(x^2-8x+16)+2(x-4)+3 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}3x^2-24x+48+2x-8+3 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}3x^2-22x+40+3 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}3x^2-22x+43\end{aligned} $$ | |
① | Find $ \left(x-4\right)^2 $ using formula. $$ (A - B)^2 = \color{blue}{A^2} - 2 \cdot A \cdot B + \color{red}{B^2} $$where $ A = \color{blue}{ x } $ and $ B = \color{red}{ 4 }$. $$ \begin{aligned}\left(x-4\right)^2 = \color{blue}{x^2} -2 \cdot x \cdot 4 + \color{red}{4^2} = x^2-8x+16\end{aligned} $$ |
② | Multiply $ \color{blue}{3} $ by $ \left( x^2-8x+16\right) $ $$ \color{blue}{3} \cdot \left( x^2-8x+16\right) = 3x^2-24x+48 $$Multiply $ \color{blue}{2} $ by $ \left( x-4\right) $ $$ \color{blue}{2} \cdot \left( x-4\right) = 2x-8 $$ |
③ | Combine like terms: $$ 3x^2 \color{blue}{-24x} + \color{red}{48} + \color{blue}{2x} \color{red}{-8} = 3x^2 \color{blue}{-22x} + \color{red}{40} $$ |
④ | Combine like terms: $$ 3x^2-22x+ \color{blue}{40} + \color{blue}{3} = 3x^2-22x+ \color{blue}{43} $$ |