\(a-b=2a+2b\Rightarrow-a=3b\Rightarrow a=-3b\Rightarrow\frac{a}{b}=-3\)
=>\(a-b=-3\left(1\right);2\left(a+b\right)=-3\Rightarrow a+b=\frac{-3}{2}\left(2\right)\)
Từ (1) và (2) => \(a-b+a+b=-3+\frac{-3}{2}\Rightarrow2a=\frac{-9}{2}\Rightarrow a=\frac{-9}{4}\Rightarrow b=\frac{3}{4}\)
Vậy ................