$\frac{2a+b}{2c}=\frac{a+b}{c}$

$\frac{1}{a-b}-\frac{1}{b-a}=\frac{1}{a-b}+\frac{1}{a-b}$

$\frac{\left(a-b\right)^2}{b-a}=\frac{-\left(b-a\right)^2}{b-a}$

$\frac{\left(2a-2b\right)^2}{a-b}=2a-2b$