$$ \begin{aligned} 10000+220(x-30) &= 280x&& \text{simplify left side} \\[1 em]10000+220x-6600 &= 280x&& \\[1 em]220x+3400 &= 280x&& \text{move the $ \color{blue}{ 280x } $ to the left side and $ \color{blue}{ 3400 }$ to the right} \\[1 em]220x-280x &= -3400&& \text{simplify left side} \\[1 em]-60x &= -3400&& \text{ divide both sides by $ -60 $ } \\[1 em]x &= \frac{-3400}{-60}&& \\[1 em]x &= \frac{170}{3}&& \\[1 em] \end{aligned} $$

This page was created using