x²-x=7/4
x²-x+1/4=7/4+1/4
(x-1/2)²=2
x-1/2=±√2
x=(1-2√2)/2,x=(1+2√2)/2
x²-2√3x+3=0
(x-√3)²=0
x--√3=0
x=√3问题补充： 解方程9y²-18y-4=0谢谢了~~~采纳我，重新问