Tap the blue circles to see an explanation.
| $$ \begin{aligned}4(x+1)^4+132(1+x)^3+17(1+x)^2+132\cdot(1+x)+4& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}4(x^4+4x^3+6x^2+4x+1)+132(1+3x+3x^2+x^3)+17(1+2x+x^2)+132\cdot(1+x)+4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle5}{\textcircled {5}} } }}}4x^4+16x^3+24x^2+16x+4+132+396x+396x^2+132x^3+17+34x+17x^2+132+132x+4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle6}{\textcircled {6}} } }}}4x^4+148x^3+420x^2+412x+136+17+34x+17x^2+132+132x+4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle7}{\textcircled {7}} } }}}4x^4+148x^3+437x^2+446x+153+132+132x+4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle8}{\textcircled {8}} } }}}4x^4+148x^3+437x^2+578x+285+4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle9}{\textcircled {9}} } }}}4x^4+148x^3+437x^2+578x+289\end{aligned} $$ | |
| ① | $$ (x+1)^4 = (x+1)^2 \cdot (x+1)^2 $$ |
| ② | Find $ \left(x+1\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}{ 1 }$. $$ \begin{aligned}\left(x+1\right)^2 = \color{blue}{x^2} +2 \cdot x \cdot 1 + \color{red}{1^2} = x^2+2x+1\end{aligned} $$ |
| ③ | Multiply each term of $ \left( \color{blue}{x^2+2x+1}\right) $ by each term in $ \left( x^2+2x+1\right) $. $$ \left( \color{blue}{x^2+2x+1}\right) \cdot \left( x^2+2x+1\right) = x^4+2x^3+x^2+2x^3+4x^2+2x+x^2+2x+1 $$ |
| ④ | Combine like terms: $$ x^4+ \color{blue}{2x^3} + \color{red}{x^2} + \color{blue}{2x^3} + \color{green}{4x^2} + \color{orange}{2x} + \color{green}{x^2} + \color{orange}{2x} +1 = x^4+ \color{blue}{4x^3} + \color{green}{6x^2} + \color{orange}{4x} +1 $$Find $ \left(1+x\right)^3 $ using formula $$ (A + B) = A^3 + 3A^2B + 3AB^2 + B^3 $$where $ A = 1 $ and $ B = x $. $$ \left(1+x\right)^3 = 1^3+3 \cdot 1^2 \cdot x + 3 \cdot 1 \cdot x^2+x^3 = 1+3x+3x^2+x^3 $$Find $ \left(1+x\right)^2 $ using formula. $$ (A + B)^2 = \color{blue}{A^2} + 2 \cdot A \cdot B + \color{red}{B^2} $$where $ A = \color{blue}{ 1 } $ and $ B = \color{red}{ x }$. $$ \begin{aligned}\left(1+x\right)^2 = \color{blue}{1^2} +2 \cdot 1 \cdot x + \color{red}{x^2} = 1+2x+x^2\end{aligned} $$ |
| ⑤ | Multiply $ \color{blue}{4} $ by $ \left( x^4+4x^3+6x^2+4x+1\right) $ $$ \color{blue}{4} \cdot \left( x^4+4x^3+6x^2+4x+1\right) = 4x^4+16x^3+24x^2+16x+4 $$Multiply $ \color{blue}{132} $ by $ \left( 1+3x+3x^2+x^3\right) $ $$ \color{blue}{132} \cdot \left( 1+3x+3x^2+x^3\right) = 132+396x+396x^2+132x^3 $$Multiply $ \color{blue}{17} $ by $ \left( 1+2x+x^2\right) $ $$ \color{blue}{17} \cdot \left( 1+2x+x^2\right) = 17+34x+17x^2 $$Multiply $ \color{blue}{132} $ by $ \left( 1+x\right) $ $$ \color{blue}{132} \cdot \left( 1+x\right) = 132+132x $$ |
| ⑥ | Combine like terms: $$ 4x^4+ \color{blue}{16x^3} + \color{red}{24x^2} + \color{green}{16x} + \color{orange}{4} + \color{orange}{132} + \color{green}{396x} + \color{red}{396x^2} + \color{blue}{132x^3} = \\ = 4x^4+ \color{blue}{148x^3} + \color{red}{420x^2} + \color{green}{412x} + \color{orange}{136} $$ |
| ⑦ | Combine like terms: $$ 4x^4+148x^3+ \color{blue}{420x^2} + \color{red}{412x} + \color{green}{136} + \color{green}{17} + \color{red}{34x} + \color{blue}{17x^2} = \\ = 4x^4+148x^3+ \color{blue}{437x^2} + \color{red}{446x} + \color{green}{153} $$ |
| ⑧ | Combine like terms: $$ 4x^4+148x^3+437x^2+ \color{blue}{446x} + \color{red}{153} + \color{red}{132} + \color{blue}{132x} = 4x^4+148x^3+437x^2+ \color{blue}{578x} + \color{red}{285} $$ |
| ⑨ | Combine like terms: $$ 4x^4+148x^3+437x^2+578x+ \color{blue}{285} + \color{blue}{4} = 4x^4+148x^3+437x^2+578x+ \color{blue}{289} $$ |