Question

1/a^2+ab - 1/ab-a^2​

Answer 1

$\frac{1}{a^{2}+ab }-\frac{1}{ab-a^{2}} =\frac{1}{a(a+b)}-\frac{1}{a(b-a)}=\frac{b-a-a-b}{a(a+b)(b-a)}=\frac{-2a}{a(b^{2}-a^{2})}=\frac{2}{a^{2}-b^{2}}$