2x²+3x=3
2(x²+3x/2)=3
x²+3x/2=3/2
x²+3x/2+(3/4)²=3/2+(3/4)²
(x+3/4)²=33/16
x+3/4=±√(33/16)
x+3/4=±√33/4
x=(-3+√33)/4或x=(-3-√33)/4