用公式法解下列方程～1.x^2-3=-2x2.-2m^2+3m+4=03.3/2a^2-a-1/4=04.8y^2-2y-15=0

Question

用公式法解下列方程～
1.x^2-3=-2x
2.-2m^2+3m+4=0
3.3/2a^2-a-1/4=0
4.8y^2-2y-15=0

Answer 1

1. x^2-3=-2x
x^2+2x-3=0
2a分之-b加减根号b^2-4ac
2分之-2加减根号16
x1=2 x2=-4
2. -2m^2+3m+4=0
2m^2-3m-4=0
2a分之-b加减根号b^2-4ac
4分之3加减根号36
x1=2 x2=-1
3.3/2a^2-a-1/4=0
6a^2-4a-1=0
2a分之-b加减根号b^2-4ac
12分之4加减根号40
x1=(2-根号10)/6 x2=(2加根号10)/6
4. 8y^2-2y-15=0
2a分之-b加减根号b^2-4ac
16分之2加减根号484
x1=3/2 x2=-5/4