$$ \begin{aligned} 6 \cdot \frac{x}{7}-3 &= 2x&& \text{multiply ALL terms by } \color{blue}{ 7 }. \\[1 em]7\cdot6 \cdot \frac{x}{7}-7\cdot3 &= 7\cdot2x&& \text{cancel out the denominators} \\[1 em]6x-21 &= 14x&& \text{move the $ \color{blue}{ 14x } $ to the left side and $ \color{blue}{ -21 }$ to the right} \\[1 em]6x-14x &= 21&& \text{simplify left side} \\[1 em]-8x &= 21&& \text{ divide both sides by $ -8 $ } \\[1 em]x &= -\frac{21}{8}&& \\[1 em] \end{aligned} $$

This page was created using