$$ \begin{aligned} 37 &= -18+5z&& \text{ swap the left and right side of the equation } \\[1 em]-18+5z &= 37&& \text{ move -18 to the right } \\[1 em]5z &= 37+18&& \\[1 em]5z &= 55&& \text{ divide both sides by $ 5 $ } \\[1 em]z &= \frac{55}{5}&& \\[1 em]z &= 11&& \\[1 em] \end{aligned} $$