数学题！~简单的！~高悬赏！~

原式等于：
6.24*102又4/5+（36/5）*6.24-624
=6.24*（102*5+4+36）/5-624
=6.24*110-6.24*100
=6.24*10
=62.4

6.24×102又4/5+18/25×62.4-624
=6.24*(100+14/5)+18/25*62.4-624
=624+6.24*(14/5)+18/25*62.4-624
=6.24*(14/5)+18/25*62.4
=6.24(14/5+180/25)
=6.24(70/25+180/25)
=6.24*10
=62.4

提出624然后分数划成小数。就是624×（1.028+0.072-1）最后是62.4