解方程(1)4x²=9(2)2(x+1)²-4=0(3)x²-4x+1=0(4)2x²+2x=1(5)x²-x-6=0
解方程(1)4x²=9
(2)2(x+1)²-4=0
(3)x²-4x+1=0
(4)2x²+2x=1
(5)x²-x-6=0
1)4x²=9
x²=9/4
x1=3/2,x2=-3/2
2)x²-4x+1=0
x²-4x+4=3
(x-2)²=3
x-2=√3或x-2=-√3
x1=√3+2,x2=-√3+2
3)2x²+2x=1
x²+x=1/2
x²+x+1/4=3/4
(x+1/2)²=3/4
x+1/2=1/2√3或x+1/2=-1/2√3
x1=(√3-1)/2或x2=(-√3-1)/2
4)x²-x-6=0
(x-3)(x+2)=0
x1=3,x2=-2
(1)解X2=9/4 x=3/2或-3/2
(2)解(x+1)2=2 x+1=正负根号2 x=正负根号2-1
(3)解(x-2)2=3 x-2=正负根号3 x=正负根号3+2
(4)解(x+1/2)2=3/4 x+1/2=正负根号3/4 x=正负根号3/4-1/2
(5)解(X-3)(x+2)=0 x=3 或x=-2
(1)4x²=9
2x=3 2x=-3
∴x=3/2 x=-3/2
(2)2(x+1)²-4=0
(x+1)²=2
∴x+1=√2 x+1=-√2
∴x=-1+√2 x=-1-√2
(3)x²-4x+1=0
x²-4x+4=3
(x-2)²=3
x-2=√3 x-2=-√3
x=2+√3 x=2-√3
(4)2x²+2x=1
x²+x=1/2
x²+x+1/4=3/4
(x+1/2)²=3/4
x=-1/2+√3/2 x=-1/2-√3/2
(5)x²-x-6=0
(x-3)(x+2)=0
∴x=3 x=-2