Question

配方法解:2X^2+1=3X。过程？

Answer 1

2x^2-3x+1=0
左右同时除以2，x^2-3/2x+1/2=0
移项，x^2-3/2x=-1/2
两边同加（3/4)^2, x^2-3/2x+(3/4)^2=-1/2+(3/4)^2
(x-3/4)^2=1/16
两边同时开方，x-3/4=±1/4
x=1或x=1/2

Answer 2

2x²+1=3x
2x²-3x+1=0
2(x-3/4)²-9/8+1=0
∴2(x-3/4)²=1/8
∴x-3/4=±1/4
x=3/4±1/4
x=1/2或者1

其实你学到最后可以用公式带，这样快多了

Answer 3

2x^2-3x=-1
x^2-(3/2)x=-1/2
x^2-2[(3/2)/2]x+[(3/2)/2]^2=-1/2+[(3/2)/2]^2

(x-3/4)^2=-1/2+9/16
(x-3/4)^2=1/16
两边开方
x-3/4=±1/4
x=3/4±1/4
x=1/2或者1

Answer 4

2x²+1=3x
2x²-3x+1=0
2(x-3/4)²-9/8+1=0
∴2(x-3/4)²=1/8

∴x-3/4=±1/4

∴x=1或1/2

Answer 5

2X^2+1=3X
2X^2-3X=-1
X^2s-3/2X=-1/2
(X-3/4)^2=-1/2+9/16
x-3/4=+-1/4
x=1/2或1