Ecuatia de gradul al II-lea se descompune astfel:
ax²+bx+c=a(x-x1)(x-x2), Δ>0
ax²+bx+c=a(x-x1)², Δ=0
ax²+bx+c nu se poate descompune in R, daca Δ<0
In exercitiul tau:
3x²-4x-4=0
Δ=16-4*(-4)*3=16+48=64
x1=(4+8)/6=12/6=2
x2=(4-8)/6=-4/6=-2/3
3x²-4x-4=3(x-2)(x+2/3)
