Odpowiedź :
y=-5x²+30x-40 |:(-5)
y=x²-6x+8
Δ=(-6)²-4·1·8
Δ=36-32
Δ=4
p=-b/2a=6/(2·1)=6/2=3
q=-Δ/4a=-4/(4·1)=-4/4=-1
W=(p,q)→W=(3,-1)
y=-5x²+30x-40 |:(-5)
y=x²-6x+8
Δ=(-6)²-4·1·8
Δ=36-32
Δ=4
p=-b/2a=6/(2·1)=6/2=3
q=-Δ/4a=-4/(4·1)=-4/4=-1
W=(p,q)→W=(3,-1)