2/3a-(2/3a-2/3b)-3/4b

问题描述:

2/3a-(2/3a-2/3b)-3/4b

2/3a-(2/3a-2/3b)-3/4b
=2/3a-2/3a+2/3b-3/4b
=(2/3-2/3)a+(2/3-3/4)b
=-1/12b

2/3a-(2/3a-2/3b)-3/4b
=2/3a-2/3a+2/3b-3/4b
=-1/12b

=2/3a-2/3a+2/3b-3/4b
=-1/12b