-2y²+3=二分之一y
-4y²+6=y
4y²+y-6=0
(2y)²+y+(1/4)²=6+1/16
(2y+1/4)²=97/16
2y+1/4=±√97/4
2y=-1/4±√97/4
y1=(-1+√97)/8 y1=(-1-√97)/8