| $$ \begin{aligned}\frac{x^2+13+36}{x^2-7x+10}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{x^2+49}{x^2-7x+10}\end{aligned} $$ | |
| ① | Simplify numerator $$ x^2+ \color{blue}{13} + \color{blue}{36} = x^2+ \color{blue}{49} $$ |