| $$ \begin{aligned}\frac{x^2-12x+36}{5x-30}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{x-6}{5}\end{aligned} $$ | |
| ① | Simplify $ \dfrac{x^2-12x+36}{5x-30} $ to $ \dfrac{x-6}{5} $. Factor both the denominator and the numerator, then cancel the common factor. $\color{blue}{x-6}$. $$ \begin{aligned} \frac{x^2-12x+36}{5x-30} & =\frac{ \left( x-6 \right) \cdot \color{blue}{ \left( x-6 \right) }}{ 5 \cdot \color{blue}{ \left( x-6 \right) }} = \\[1ex] &= \frac{x-6}{5} \end{aligned} $$ |