Question

4x2-x-9=0 用配方法解方程

要有过程

Answer 1

解：4(X²-X/4-9/4)=0
X²-X/4=9/4
X²-X/4+1/64=145/64
(X-1/8)²=145/64
X=1/8+1/8√145 或 X=1/8-1/8√145

Answer 2

4x^2-2*2x*1/4+1/16-1/16-9=0

(2x-1/4)^2-145/16=0

(2x-1/4)^2=145/16

开方

2x-1/4=√145/4

x=（√145+1）/8

Answer 3

4x^2-x-9=0
x^2-(1/4)x=9/4
x^2-2×(1/8)x+(1/8)^2=9/4+(1/8)^2
(X-1/8)^2=145/64
X-1/8=±√145/8
X=(1±√145)/8

Answer 4

8-x-9+9=0+9
8-x+x=9+x
8-9=x-9
x=-1