a) \(x^2-x-12\)
\(=x^2-4x+3x-12\)
\(=\left(x^2-4x\right)+\left(3x-12\right)\)
\(=x\left(x-4\right)+3\left(x-4\right)\)
\(=\left(x+3\right)\left(x-4\right)\)
b) \(x^2-5x-24\)
\(=x^2-8x+3x-24\)
\(=\left(x^2-8x\right)+\left(3x-24\right)\)
\(=x\left(x-8\right)+3\left(x-8\right)\)
\(=\left(x+3\right)\left(x-8\right)\)
c) \(3x^2+13x-10\)
\(=3x^2+15x-2x-10\)
\(=\left(3x^2+15x\right)-\left(2x+10\right)\)
\(=3x\left(x+5\right)-2\left(x+5\right)\)
\(=\left(3x-2\right)\left(x+5\right)\)
a: =x^2-4x+3x-12
=x(x-4)+3(x-4)
=(x-4)(x+3)
b: =x^2-8x+3x-24
=x(x-8)+3(x-8)
=(x-8)(x+3)
c: =3x^2+15x-2x-10
=3x(x+5)-2(x+5)
=(x+5)(3x-2)