题目

用配方法解下列一元二次方程 (1) x^2+7/4x+1/2=0 (2)1/3x^2-x-4=0 (3)6x^2-x-1=0 (4)0.4y^2+0.8y-1=0 (5)-2y^2+4y+9=0 (6)(x-1)^2-4(x-1)+3=0

提问时间：2021-02-20

答案

【1】( x + 7/8)^2 = 17/64x1 =(-7+√17)/64x2 = (-7-√17)/64【2】1/3( x +3/2 )^2 - 19/4 = 0( x + 3/2 )^2 = 57/4x1 = (-3+√57)/2x2 = (-3- √57)/2【3】6( x - 1/12 )^2 - 25/24 = 0x1 = 1/2x2 = -1/3【4】0.4(...