$$ \begin{aligned}\frac{z-2}{z^2-6z+8}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{1}{z-4}\end{aligned} $$ | |
① | Factor both the denominator and the numerator, then cancel the common factor. $\color{blue}{z-2}$. $$ \begin{aligned} \frac{z-2}{z^2-6z+8} & =\frac{ 1 \cdot \color{blue}{ \left( z-2 \right) }}{ \left( z-4 \right) \cdot \color{blue}{ \left( z-2 \right) }} = \\[1ex] &= \frac{1}{z-4} \end{aligned} $$ |