a) \(x^2+5x-6=x^2-x+6x-6\)
=\(\left(x^2-x\right)+\left(6x-6\right)\)
\(=x\left(x-1\right)+6\left(x-1\right)\)
\(=\left(x-1\right)\left(x+6\right)\)
b) \(5x^2+5xy-x-y=\left(5x^2+5xy\right)-\left(x+y\right)\)
\(=5x\left(x+y\right)-\left(x+y\right)\)
\(=\left(x+y\right)\left(5x-1\right)\)
c) \(7x-6x^2-2=-\left(6x^2-7x+2\right)\)
\(=-\left(6x^2-4x-3x+2\right)\)
\(=-\left[\left(6x^2-4x\right)-\left(3x-2\right)\right]\)
\(=-\left[2x\left(3x-2\right)-\left(3x-2\right)\right]\)
\(=-\left(3x-2\right)\left(2x-1\right)\)
Câu a : \(x^2+5x-6\)
\(=x^2-x+6x-6\)
\(=x\left(x-1\right)+6\left(x-1\right)\)
\(=\left(x-1\right)\left(x+6\right)\)
Câu b : \(5x^2+5xy-x-y\)
\(=5x\left(x+y\right)-\left(x+y\right)\)
\(=\left(x+y\right)\left(5x-1\right)\)
Câu c : \(7x-6x^2-2\)
\(=-6x^2+7x-2\)
\(=-6x^2+3x+4x-2\)
\(=-3x\left(2x-1\right)+2\left(2x-1\right)\)
\(=\left(2x-1\right)\left(2-3x\right)\)