1)(х-1)(х+2)=0
2)(2х+3)(х-4)=0

(x-1)(x+2)=0x²+2x-x-2=0x²+x-2=0D=1-4*(-2)=9x₁=(-1+3)/2=1x₂=(-1-3)/2=-2(2x+3)(x-4)=02x²-8x+3x-12=02x²-5x-12=0D=25-4*2*(-12)=121x₁=(5+11)/4=4x₂=(5-11)/4=-6/4=-3/2=-1.5