| $$ \begin{aligned}\frac{2x^2+8x-10}{2x^2+12x+10}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{x-1}{x+1}\end{aligned} $$ | |
| ① | Simplify $ \dfrac{2x^2+8x-10}{2x^2+12x+10} $ to $ \dfrac{x-1}{x+1} $. Factor both the denominator and the numerator, then cancel the common factor. $\color{blue}{2x+10}$. $$ \begin{aligned} \frac{2x^2+8x-10}{2x^2+12x+10} & =\frac{ \left( x-1 \right) \cdot \color{blue}{ \left( 2x+10 \right) }}{ \left( x+1 \right) \cdot \color{blue}{ \left( 2x+10 \right) }} = \\[1ex] &= \frac{x-1}{x+1} \end{aligned} $$ |