-3/5-1/2+3/4-2/5+1/2等于多少

问题描述:

-3/5-1/2+3/4-2/5+1/2等于多少

-3/5-1/2+3/4-2/5+1/2
=-(3/5+2/5)+(1/2-1/2)+3/4
=-1+0+3/4
=-1/40-1/2-(+2/5)-(-3/4)-(+1/4) 这道题怎么写?采纳我,然后重新问