$$ \begin{aligned}\frac{3x-9}{4x-12}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{3}{4}\end{aligned} $$ | |
① | Factor both the denominator and the numerator, then cancel the common factor. $\color{blue}{x-3}$. $$ \begin{aligned} \frac{3x-9}{4x-12} & =\frac{ 3 \cdot \color{blue}{ \left( x-3 \right) }}{ 4 \cdot \color{blue}{ \left( x-3 \right) }} = \\[1ex] &= \frac{3}{4} \end{aligned} $$ |