1、0.8888*10.4-0.1111*3.2=0.8888*10.4-0.8888*0.4=0.8888*(10.4-0.4)=8.888
2、(36963-369.63)/(24642-246.42)=[369.63*(100-1)]/[246.42*(100-1)]
=369.63/246.42(扩大100倍再约9、37)
=111/74
3、(1+1.8)+(2+1.8*2)+(3+1.8*3)+···+(100+1.8*100)
=(1+2+3+…+100)+(1.8*1+1.8*2+1.8*3+…1.8*100)
=5050+1.8*(1+2+3+…+100)
=5050+1.8*5050
=5050*(1+1.8)
=5050*2.8
=14140
4、再核对下是不是数字打错了?