ax²+bx+c=a(x-x1)(x-x2)
x²+3x+2=0
a=1
b=3
c=2
∆=b²-4ac=3²-4*2*1=9-8=1
x1=(-b+√∆)/2a=(-3+√1)/2*1=(-3+1)/2=-2/2=-1
x2=(-b-√∆)/2a=(-3-√1)/2*1=(-3-1)/2=-4/2=-2
x1=-1 si x2=-2
→pentru ecuatie S={-2;-1)}
→pentru descompunerea in factori:
x²+3x+2=1*[x-(-1)][x-(-2)]=(x+1)(x+2)
