(1+1*1.2)+(2+2*1.2)+(3+3*1.2)+.+(100+1*10.2)
问题描述：
(1+1*1.2)+(2+2*1.2)+(3+3*1.2)+.+(100+1*10.2)
答
=1*(1+1.2)+2*(1+1.2)+#*(1+1.2)+...+100*(1+1.2)
=(1+2+3+...=100)*(1+1.2)
=100*101/2*2.2
=11110