$$ \begin{aligned} \frac{x}{4}-\frac{1}{5} &= \frac{4x+3}{20}&& \text{multiply ALL terms by } \color{blue}{ 20 }. \\[1 em]20 \cdot \frac{x}{4}-20\cdot\frac{1}{5} &= 20 \cdot \frac{4x+3}{20}&& \text{cancel out the denominators} \\[1 em]5x-4 &= 4x+3&& \text{move the $ \color{blue}{ 4x } $ to the left side and $ \color{blue}{ -4 }$ to the right} \\[1 em]5x-4x &= 3+4&& \text{simplify left and right hand side} \\[1 em]x &= 7&& \\[1 em]x &= 7&& \\[1 em] \end{aligned} $$

This page was created using