第1个回答 2022-10-22
1/1×4+1/4×7+1/7×10+1/10×13+...+1/97×100
=1/3×(3/1×4+3/4×7+3/7×10+3/10×13+...+3/97*×100)
=1/3×[(1/1-1/4)+(1/4-1/7)+(1/7-1/10)+(1/10-1/13)+……+(3/97-3/100)]
=1/3×(1/1-1/4+1/4-1/7+1/7-1/10+1/10-1/13+……+1/97-1/100)
=1/3×(1/1-1/100)
=1/3×99/100
=33/100,3,1/3（1—1/4+1/4—1/7……………—/97+1/97+1/100）=1/3（1—1/100）=33/100,2,原式=1/3【(1-1/4)+(1/4-1/7)+(1/7-1/10)+……+(1/97 -1/1000]
=1/3[1-1/100]=1/3 *33/100=11/100
【【不清楚，再问；满意， 请采纳！祝你好运开！！】】,1,1/1*4+1/4*7+1/7*10+1/10*13+...+1/97*100
=1/3[（1-1/4）+（1/4-1/7）+……+（1/97-1/100）]
=1/3[1-1/4+1/4-1/7+1/7+……+1/97-1/100]
=1/3(1-1/100)
=33/1001/3是哪来的，运用了神马公式1/4*7=1/28...,1,1/(1×4)+1/(4×7)+...+1/(97×100)
=(1/3)(1-1/4+1/4-1/7+...+1/97-1/100)
=(1/3)(1-1/100)
=(1/3)(99/100)
=33/100,1,