解方程:81x^2-4=0;(x-2)^2=4x-8.
问题描述:
解方程:81x^2-4=0;(x-2)^2=4x-8.
答
81x^2-4=0
81x^2=4
x^2=4/81
x=2/9或x=-2/9
(x-2)^2=4x-8
x^2-4x+4=4x-8
x^2-8x+12=0
(x-6)(x-2)=0
x=6或x=2