\(a,=x^2-3x+2x-6=\left(x-3\right)\left(x+2\right)\\ b,=4x^2-4x+5x-5=\left(x-1\right)\left(4x+5\right)\\ c,=2x^2-6x-x+3=\left(x-3\right)\left(2x-1\right)\\ d,=3x^2-15x-x+5=\left(x-5\right)\left(3x-1\right)\)
a) x2-x-6
=x2-3x+2x-6
=x(x-3)+2(x-3)
=(x+2)(x-3)

