Tap the blue circles to see an explanation.
$$ \begin{aligned}(x+4)^4& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}x^4+16x^3+96x^2+256x+256\end{aligned} $$ | |
① | $$ (x+4)^4 = (x+4)^2 \cdot (x+4)^2 $$ |
② | 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 }$. $$ \begin{aligned}\left(x+4\right)^2 = \color{blue}{x^2} +2 \cdot x \cdot 4 + \color{red}{4^2} = x^2+8x+16\end{aligned} $$ |
③ | Multiply each term of $ \left( \color{blue}{x^2+8x+16}\right) $ by each term in $ \left( x^2+8x+16\right) $. $$ \left( \color{blue}{x^2+8x+16}\right) \cdot \left( x^2+8x+16\right) = x^4+8x^3+16x^2+8x^3+64x^2+128x+16x^2+128x+256 $$ |
④ | Combine like terms: $$ x^4+ \color{blue}{8x^3} + \color{red}{16x^2} + \color{blue}{8x^3} + \color{green}{64x^2} + \color{orange}{128x} + \color{green}{16x^2} + \color{orange}{128x} +256 = \\ = x^4+ \color{blue}{16x^3} + \color{green}{96x^2} + \color{orange}{256x} +256 $$ |