计算:(1/2+1/3+1/4+…+1/99+1/100)+(2/3+2/4+2/5+…+2/99+2/100)+…+(98/99+98/100).
问题描述:
计算:(
+1 2
+1 3
+…+1 4
+1 99
)+(1 100
+2 3
+2 4
+…+2 5
+2 99
)+…+(2 100
+98 99
). 98 100
答
原式=12+(13+23)+(14+24+34)+(15+25+35+45)+(16+26+36+46+56)+(17+27+37+47+57+67)+…+(1100+2100+3100+4100+…+98100)=12+1+1.5+2+2.5+3+…+48.5=(0.5+48.5)×97÷2=2376.5.