化简3a+[2b-3(c-1)]
问题描述：
化简3a+[2b-3(c-1)]
答
3a+[2b-3(c-1)]
=3a+[2b-3c+3]
=3a+2b-3c+3
拆括号时注意括号前是减号时,去括号同时把减号改成加号,如果括号前是加号时,去括号符号不变.