怎么做的啊? 财富值48

2016-10-19 20:06发布

-xy^2+3xy^2         

3a-2a+2/3a

2条回答

-xy^2+3xy^2       

=(3-1)xy^2

=2xy^2

 

-xy^2+3xy^2        

=(-1+3)xy^2

=2xy^2


3a-2a+2/3a

=(3-2+2/3)a

=5a/3

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