$$ \begin{aligned}\frac{x^2-9x+14}{20-5x^2}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{x-7}{-5x-10}\end{aligned} $$ | |
① | Factor both the denominator and the numerator, then cancel the common factor. $\color{blue}{x-2}$. $$ \begin{aligned} \frac{x^2-9x+14}{20-5x^2} & =\frac{ \left( x-7 \right) \cdot \color{blue}{ \left( x-2 \right) }}{ \left( -5x-10 \right) \cdot \color{blue}{ \left( x-2 \right) }} = \\[1ex] &= \frac{x-7}{-5x-10} \end{aligned} $$ |