2a+(4a-5b)-3(a-2b)
问题描述：
2a+(4a-5b)-3(a-2b)
答
2a+(4a-5b)-3(a-2b)
=2a+4a-5b-3a+6b
=3a+b
2a+(4a-5b)-3(a-2b)
2a+(4a-5b)-3(a-2b)
=2a+4a-5b-3a+6b
=3a+b