Tap the blue circles to see an explanation.
$$ \begin{aligned}(2+x)^2(8+2x+\frac{4}{x})& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}(4+4x+x^2)(8+2x+\frac{4}{x}) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}(4+4x+x^2)\frac{2x^2+8x+4}{x} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{2x^4+16x^3+44x^2+48x+16}{x}\end{aligned} $$ | |
① | Find $ \left(2+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}{ 2 } $ and $ B = \color{red}{ x }$. $$ \begin{aligned}\left(2+x\right)^2 = \color{blue}{2^2} +2 \cdot 2 \cdot x + \color{red}{x^2} = 4+4x+x^2\end{aligned} $$ |
② | Step 1: Write $ 8+2x $ as a fraction by putting $ \color{red}{ 1 } $ in the denominator. Step 2: To add raitonal expressions, both fractions must have the same denominator. |
③ | Step 1: Write $ 4+4x+x^2 $ as a fraction by putting $ \color{red}{1} $ in the denominator. Step 2: Multiply numerators and denominators. Step 3: Simplify numerator and denominator. $$ \begin{aligned} 4+4x+x^2 \cdot \frac{2x^2+8x+4}{x} & \xlongequal{\text{Step 1}} \frac{4+4x+x^2}{\color{red}{1}} \cdot \frac{2x^2+8x+4}{x} \xlongequal{\text{Step 2}} \frac{ \left( 4+4x+x^2 \right) \cdot \left( 2x^2+8x+4 \right) }{ 1 \cdot x } = \\[1ex] & \xlongequal{\text{Step 3}} \frac{ 8x^2+32x+16+8x^3+32x^2+16x+2x^4+8x^3+4x^2 }{ x } = \frac{2x^4+16x^3+44x^2+48x+16}{x} \end{aligned} $$ |