6.88×3.43+ 6.86×1.56
=3.44×6.86+ 6.86×1.56
=（3.44+1.56）+×6.86
=5×6.86
=34.3+×6.86什么意思？？？？？？？？？？6.88×3.43+ 6.86×1.56=3.44×6.86+ 6.86×1.56=（3.44+1.56）×6.86=5×6.86=34.3