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