x2−(α+β)x+αβ=0x^{2}-(\alpha+\beta) x+\alpha \beta=0x2−(α+β)x+αβ=0
x2+(α+β)x+αβ=0x^{2}+(\alpha+\beta) x+\alpha \beta=0x2+(α+β)x+αβ=0
x2−(α+β)x−αβ=0x^{2}-(\alpha+\beta) x-\alpha \beta=0x2−(α+β)x−αβ=0
x2+(α+β)x−αβ=0x^{2}+(\alpha+\beta) x-\alpha \beta=0x2+(α+β)x−αβ=0