$$ \begin{aligned}\frac{3x^2+11x+10}{3x^2+20x+25}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{x+2}{x+5}\end{aligned} $$ | |
① | Factor both the denominator and the numerator, then cancel the common factor. $\color{blue}{3x+5}$. $$ \begin{aligned} \frac{3x^2+11x+10}{3x^2+20x+25} & =\frac{ \left( x+2 \right) \cdot \color{blue}{ \left( 3x+5 \right) }}{ \left( x+5 \right) \cdot \color{blue}{ \left( 3x+5 \right) }} = \\[1ex] &= \frac{x+2}{x+5} \end{aligned} $$ |