a/ \(\sqrt{x^2-x-6}=\sqrt{x-3}\)\(\Rightarrow x^2-x-6=x-3\Rightarrow x^2-2x-3=0\)
\(\Rightarrow\left(x-3\right)\left(x+1\right)=0\Rightarrow x=3\)hoặc \(x=-1\)
Vậy x = 3, x = -1
b/ \(\sqrt{x^2-x}=x-5\Rightarrow x^2-x=x^2-10x+25\Rightarrow9x=25\Rightarrow x=\frac{25}{9}\)
Vậy x = 25/9