$$ \begin{aligned} 7x+5 &= 8x&& \text{move the $ \color{blue}{ 8x } $ to the left side and $ \color{blue}{ 5 }$ to the right} \\[1 em]7x-8x &= -5&& \text{simplify left side} \\[1 em]-x &= -5&& \text{switch signs on both sides} \\[1 em]x &= 5&& \\[1 em] \end{aligned} $$