一元二次方程3x^2+2x-2=3(x+__)^2+(__)后面那个空到底填-16/3 还是 -7/3?别忘了等式后面是等于3_数学解答

一元二次方程3x^2+2x-2=3(x+__)^2+(__)
后面那个空到底填-16/3 还是 -7/3?别忘了等式后面是等于3

人气：109 ℃　时间：2020-02-06 00:55:51

解答

先都提取3
则3x^2+2x-2
=3(x²+2/3x-2/3)
=3(x²+2/3x+1/9-1/9-2/3)
=3(x²+2/3x+1/9)-3(1/9+2/3)
=3(x+1/3)²-7/3