Tap the blue circles to see an explanation.
| $$ \begin{aligned}(2+s)^2(8+2x+\frac{4}{x})& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}(4+4s+s^2)(8+2x+\frac{4}{x}) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}(4+4s+s^2)\frac{2x^2+8x+4}{x} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{2s^2x^2+8s^2x+8sx^2+4s^2+32sx+8x^2+16s+32x+16}{x}\end{aligned} $$ | |
| ① | Find $ \left(2+s\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}{ s }$. $$ \begin{aligned}\left(2+s\right)^2 = \color{blue}{2^2} +2 \cdot 2 \cdot s + \color{red}{s^2} = 4+4s+s^2\end{aligned} $$ |
| ② | Add $8+2x$ and $ \dfrac{4}{x} $ to get $ \dfrac{ \color{purple}{ 2x^2+8x+4 } }{ x }$. 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 | Multiply $4+4s+s^2$ by $ \dfrac{2x^2+8x+4}{x} $ to get $ \dfrac{2s^2x^2+8s^2x+8sx^2+4s^2+32sx+8x^2+16s+32x+16}{x} $. Step 1: Write $ 4+4s+s^2 $ as a fraction by putting $ \color{red}{1} $ in the denominator. Step 2: Multiply numerators and denominators. Step 3: Simplify numerator and denominator. $$ \begin{aligned} 4+4s+s^2 \cdot \frac{2x^2+8x+4}{x} & \xlongequal{\text{Step 1}} \frac{4+4s+s^2}{\color{red}{1}} \cdot \frac{2x^2+8x+4}{x} \xlongequal{\text{Step 2}} \frac{ \left( 4+4s+s^2 \right) \cdot \left( 2x^2+8x+4 \right) }{ 1 \cdot x } = \\[1ex] & \xlongequal{\text{Step 3}} \frac{ 8x^2+32x+16+8sx^2+32sx+16s+2s^2x^2+8s^2x+4s^2 }{ x } = \frac{2s^2x^2+8s^2x+8sx^2+4s^2+32sx+8x^2+16s+32x+16}{x} \end{aligned} $$ |