Odpowiedź:
a)y=(x-2)(x+4)
y=x²+4x-2x-8
y=x²+2x-8
a=1,b=2,c=-8
Δ=b²-4ac=2²-4*1*(-8)=4+32=36
√Δ=√36=6
x₁=-b+√Δ/2a=-2+6/2=4/2=2
x₁=2
x₂=-b+√Δ/2a=-2-6/2=-8/2=-4
x₂=-4
b)y=-2x²-8x+6
a=-2,b=-8,c=6
Δ=b²-4ac=64+48=112
√Δ=√112=√16*7=4√7
x=₁-b+√Δ/2a=8+4√7/(-4)=4(2+√7)/(-4)=-2-√7
x₁=-2-√7
x₂=-b-√Δ/2a=8-4√7/-4=4(2-√7)/(-4)=-2+√7
x₂=-2+√7
c)y=x²-11x
a=1,b=-11,c=0
Δ=b²-4ac=(-11)²-4*1*0
Δ=121
√Δ=√121=11
x₁=-b+√Δ/2a=11+11/2=22/2=11
x₁=11
x₂=-b-√Δ/2a=11-11/2=0
x₂=0
Szczegółowe wyjaśnienie:
