Question

数学:用配方解这个方程2x²-5x+2=0

Answer 1

2x^2-5x+2=0
2(x^2-5/2x)+2=0
2(x^2-2x5/4x+(5/4)^2)-2(5/4)^2+2=0
2(x-5/4)^2-25/8+16/8=0
2(x-5/4)^2=9/8
(x-5/4)^2=9/16
x-5/4=±3/4
x=5/4±3/4
即x=2或x=1/2

Answer 2

2x²-5x+2=0
(2x-1)(x-2)=0
2x-1=0或x-2=0
x1=0.5
x2=2

Answer 3

1 -2
2 -1
(x-2)(2x-1)=0
x=2或x=1/2

Answer 4

俊狼猎英团队为您解答：

X^2-5/2X=-1
X^2-5/2X+(5/4)^2=-1+(5/4)^2
(X-5/4)^=9/16
X-5/4=±3/4
X1=2，X2=-1/2

Answer 5

2x^2-x-4x+2=0
x(2x-1)-2(2x-1)=0
(x-2)(2x-1)=0
x=2 or x=1/2

Answer 6

2x²-5x+2=0
方程两边都除以2得
x²-5/2x+1=0
x²-5/2x=-1
方程两边都加上(5/4)²得
x²-5/2x+(5/4)²=-1+（5/4）²
(x-5/4)²=9/16
∴x-5/4=±3/4
∴x1=1/2, x2=2