b, \(2x^2-x-6=5x-10\Leftrightarrow2x^2-6x+4=0\)
\(\Leftrightarrow\left(x-1\right)\left(2x-4\right)=0\Leftrightarrow x=1;x=2\)
c, đk : x khác -2 ; 2
\(3x^2-6x-2\left(x^2-4\right)=x^2+2x\Leftrightarrow3x^2-2x^2-6x+8=x^2+2x\)
\(\Leftrightarrow-8x=-8\Leftrightarrow x=1\)(tm)


