$$ \begin{aligned} 5x-15 &= 3(2x+5)&& \text{simplify right side} \\[1 em]5x-15 &= 6x+15&& \text{move the $ \color{blue}{ 6x } $ to the left side and $ \color{blue}{ -15 }$ to the right} \\[1 em]5x-6x &= 15+15&& \text{simplify left and right hand side} \\[1 em]-x &= 30&& \text{switch signs on both sides} \\[1 em]x &= -30&& \\[1 em] \end{aligned} $$

This page was created using