Răspuns :
a=1 b=10 c=21
Δ=b²-4ac=1²-4×10×21=1+840=841
x1= -b-√Δ = -1-√841 =-1-29 -30 -15
2a 2×1 2 2
x2=-b+√Δ = -1+√841= -1+29 = 28 = 14
2a 2 2 2
Δ=b²-4ac=1²-4×10×21=1+840=841
x1= -b-√Δ = -1-√841 =-1-29 -30 -15
2a 2×1 2 2
x2=-b+√Δ = -1+√841= -1+29 = 28 = 14
2a 2 2 2