判别式=a^2-4b=2-根号3
x1+x2=-a
x1x2=b
x1/x2=3/4
x1=3/4 x2
3/4 x2^2=b
3/4x2+x2=-a=7/4x2
代入判别式:
49/16x2^2-4*3/4 x2=2-根号3
49/16x2^2-3x2-(2-根号3)=0
解出x2=...
就得到x1=...