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