2x²+5x-1=0.希望写个步骤.
2x²+5x-1=0.希望写个步骤.
2x²+5x-1=0
x=[-5±√(5²+4×2)]÷4
x=(-5±√33)/4
∴x1=-5/4+1/4√33
x2=-5/4-1/4√33