2/3-3/8+1/3-5/8
=(2/3+1/3)-(3/8+5/8)
=1-1
=0
用交换律和结合律简算原式=2/3+1/3-(3/8+5/8)=1-1=0
简便计算2/3-3/8+1/3-5/8=(2/3+1/3)-(3/8+5/8)=1-1=0