$$3(x-2)+7 = 20-(x-1)$$

$$ \begin{aligned} 3(x-2)+7 &= 20-(x-1)&& \text{simplify left and right hand side} \\[1 em]3x-6+7 &= 20-x+1&& \\[1 em]3x+1 &= -x+21&& \text{move the $ \color{blue}{ -x } $ to the left side and $ \color{blue}{ 1 }$ to the right} \\[1 em]3x+x &= 21-1&& \text{simplify left and right hand side} \\[1 em]4x &= 20&& \text{ divide both sides by $ 4 $ } \\[1 em]x &= \frac{20}{4}&& \\[1 em]x &= 5&& \\[1 em] \end{aligned} $$

This page was created using