发布网友
共2个回答
热心网友
=31x(87+130)
=31x(200+10+7)
=6200+310+217
=6727
热心网友
31×87+13×310简便计算公式?
=31*87+130*31
=31*(87+130)
=31*217
=(30+1)*217
=6510+217
=6727