| $$ \begin{aligned}(1+\frac{x}{2})^3-(1+\frac{x}{2})& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}(1+\frac{x}{2})^3-\frac{x+2}{2}\end{aligned} $$ | |
| ① | Add $1$ and $ \dfrac{x}{2} $ to get $ \dfrac{ \color{purple}{ x+2 } }{ 2 }$. Step 1: Write $ 1 $ as a fraction by putting $ \color{red}{ 1 } $ in the denominator. Step 2: To add raitonal expressions, both fractions must have the same denominator. |