1) x^2-5x+6=0 x1+x2=5 x1*x2=6 x1=6 x2=-1
2) x^2+4x+3=0 x1+x2=-4 x1*x2=3 x1=-3 x2=-1
3)x^2-16+48=0 x1+x2=16 x1*x2=48 x1=12 x=4
4)x^2-2x-3=0 x1+x2=2 x1*x2=-3 x1=3 x2=-1
5) x^2+3x-4=0 x1+x2=-3 x1*x2=-4 x1=1 x2=-4
6)x^2+12+27=0 x1+x2=-12 x1*x2=27 x1=-3 x2=-9