(7a-2b)-【6a-(5b-2c)】+2c=
问题描述:
(7a-2b)-【6a-(5b-2c)】+2c=
答
(7a-2b)-【6a-(5b-2c)】+2c
=7a-2b-6a+5b-2c+2c
=a+3b