Tap the blue circles to see an explanation.
| $$ \begin{aligned}4(-1+x)^4+4x^4+132x\cdot(-1+x)(2x^2-2x+1)+17(1-x)^2x^2& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}4(x^4-4x^3+6x^2-4x+1)+4x^4+132x\cdot(-1+x)(2x^2-2x+1)+17(1-2x+x^2)x^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle5}{\textcircled {5}} } }}}4x^4-16x^3+24x^2-16x+4+4x^4+(-132x+132x^2)(2x^2-2x+1)+(17-34x+17x^2)x^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle6}{\textcircled {6}} } }}}8x^4-16x^3+24x^2-16x+4+(-132x+132x^2)(2x^2-2x+1)+(17-34x+17x^2)x^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle7}{\textcircled {7}} } }}}8x^4-16x^3+24x^2-16x+4-264x^3+264x^2-132x+264x^4-264x^3+132x^2+17x^2-34x^3+17x^4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle8}{\textcircled {8}} } }}}8x^4-16x^3+24x^2-16x+4+264x^4-528x^3+396x^2-132x+17x^2-34x^3+17x^4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle9}{\textcircled {9}} } }}}272x^4-544x^3+420x^2-148x+4+17x^2-34x^3+17x^4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle10}{\textcircled {10}} } }}}289x^4-578x^3+437x^2-148x+4\end{aligned} $$ | |
| ① | $$ (-1+x)^4 = (-1+x)^2 \cdot (-1+x)^2 $$ |
| ② | Find $ \left(-1+x\right)^2 $ in two steps. S1: Change all signs inside bracket. S2: Apply 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 }$. $$ \begin{aligned}\left(-1+x\right)^2& \xlongequal{ S1 } \left(1-x\right)^2 \xlongequal{ S2 } \color{blue}{1^2} -2 \cdot 1 \cdot x + \color{red}{x^2} = \\[1 em] & = 1-2x+x^2\end{aligned} $$ |
| ③ | Multiply each term of $ \left( \color{blue}{1-2x+x^2}\right) $ by each term in $ \left( 1-2x+x^2\right) $. $$ \left( \color{blue}{1-2x+x^2}\right) \cdot \left( 1-2x+x^2\right) = 1-2x+x^2-2x+4x^2-2x^3+x^2-2x^3+x^4 $$ |
| ④ | Combine like terms: $$ 1 \color{blue}{-2x} + \color{red}{x^2} \color{blue}{-2x} + \color{green}{4x^2} \color{orange}{-2x^3} + \color{green}{x^2} \color{orange}{-2x^3} +x^4 = x^4 \color{orange}{-4x^3} + \color{green}{6x^2} \color{blue}{-4x} +1 $$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}{132x} $ by $ \left( -1+x\right) $ $$ \color{blue}{132x} \cdot \left( -1+x\right) = -132x+132x^2 $$Multiply $ \color{blue}{17} $ by $ \left( 1-2x+x^2\right) $ $$ \color{blue}{17} \cdot \left( 1-2x+x^2\right) = 17-34x+17x^2 $$ |
| ⑥ | Combine like terms: $$ \color{blue}{4x^4} -16x^3+24x^2-16x+4+ \color{blue}{4x^4} = \color{blue}{8x^4} -16x^3+24x^2-16x+4 $$ |
| ⑦ | Multiply each term of $ \left( \color{blue}{-132x+132x^2}\right) $ by each term in $ \left( 2x^2-2x+1\right) $. $$ \left( \color{blue}{-132x+132x^2}\right) \cdot \left( 2x^2-2x+1\right) = -264x^3+264x^2-132x+264x^4-264x^3+132x^2 $$$$ \left( \color{blue}{17-34x+17x^2}\right) \cdot x^2 = 17x^2-34x^3+17x^4 $$ |
| ⑧ | Combine like terms: $$ \color{blue}{-264x^3} + \color{red}{264x^2} -132x+264x^4 \color{blue}{-264x^3} + \color{red}{132x^2} = 264x^4 \color{blue}{-528x^3} + \color{red}{396x^2} -132x $$ |
| ⑨ | Combine like terms: $$ \color{blue}{8x^4} \color{red}{-16x^3} + \color{green}{24x^2} \color{orange}{-16x} +4+ \color{blue}{264x^4} \color{red}{-528x^3} + \color{green}{396x^2} \color{orange}{-132x} = \\ = \color{blue}{272x^4} \color{red}{-544x^3} + \color{green}{420x^2} \color{orange}{-148x} +4 $$ |
| ⑩ | Combine like terms: $$ \color{blue}{272x^4} \color{red}{-544x^3} + \color{green}{420x^2} -148x+4+ \color{green}{17x^2} \color{red}{-34x^3} + \color{blue}{17x^4} = \\ = \color{blue}{289x^4} \color{red}{-578x^3} + \color{green}{437x^2} -148x+4 $$ |