$$ \begin{aligned} \frac{7}{10}x-8-\frac{1}{2}x &= 0&& \text{multiply ALL terms by } \color{blue}{ 10 }. \\[1 em]10 \cdot \frac{7}{10}x-10\cdot8-10\frac{1}{2}x &= 10\cdot0&& \text{cancel out the denominators} \\[1 em]7x-80-5x &= 0&& \text{simplify left side} \\[1 em]2x-80 &= 0&& \text{ move the constants to the right } \\[1 em]2x &= 80&& \text{ divide both sides by $ 2 $ } \\[1 em]x &= \frac{80}{2}&& \\[1 em]x &= 40&& \\[1 em] \end{aligned} $$

This page was created using