Răspuns:
x^2-6x+5=0
delta=b^2-4ac= (-6)^2-4×1×5=36-20=16
√delta =√16=4
x1=-b-delta/2a =6-4/2×1 =2/2=1
x2=-b+delta/2a=6+4/2×1=10/2=5
S={1;5}