1)(х-1)(х+2)=0 2)(2х+3)(х-4)=0
(x-1)(x+2)=0 x²+2x-x-2=0 x²+x-2=0 D=1-4*(-2)=9 x₁=(-1+3)/2=1 x₂=(-1-3)/2=-2 (2x+3)(x-4)=0 2x²-8x+3x-12=0 2x²-5x-12=0 D=25-4*2*(-12)=121 x₁=(5+11)/4=4 x₂=(5-11)/4=-6/4=-3/2=-1.5