ĐKXĐ:\(\forall x\in R\)
\(\sqrt{x^2+12}-\sqrt{x^2+5}=3x-5\)
\(\Leftrightarrow\sqrt{x^2+12}-4-\left(\sqrt{x^2+5}-3\right)-3x+6=0\)
\(\Leftrightarrow\frac{x^2-4}{\sqrt{x^2+12}+4}-\frac{x^2-4}{\sqrt{x^2+5}+3}-3\left(x-2\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(\frac{x+2}{\sqrt{x^2+12}+4}-\frac{x+2}{\sqrt{x^2+5}+3}-3\right)\)\(=0\)
\(\Rightarrow x=2\) (t/m)
Vậy \(x=2\)