4(a-√2)²+8=(a-√2)²+20用直接开平方解方程

问题描述:

4(a-√2)²+8=(a-√2)²+20用直接开平方解方程

4(a-√2)²+8=(a-√2)²+20 进行整理后得:
3(a-√2)=12² 等式两边同时除以3,有(a-√2)²=4
则a-√2=2或者a-√2=-2
解得a=2+√2或者a=-2+√2

4(a-√2)²+8=(a-√2)²+20
4(a-√2)²-(a-√2)²=12
3(a-√2)²=12
(a-√2)²=4
a-√2=±2
a=±2+√2

4(a-√2)²+8=(a-√2)²+20
4(a-√2)²-(a-√2)²=20 - 8
3(a-√2)²=12
(a-√2)²=4
a-√2= ±2
a = 2 + √2 或 a = -2 + √2