(1) 1×4/1+4×7/1+7×10+…+97×100/1
问题描述:
(1) 1×4/1+4×7/1+7×10+…+97×100/1
(2) 1又1/10+2又1/40+4又1/88+6又1/154
(3) (1-1/2005)+(1-1/2005×2)+(1-1/2005×3)+…(1-1/2005×2004)
答
1.是否抄错题了?
应该是分子分母倒转来写了吧?
这样答案应该是:(1/3)*[(1-1/4)+(1/4-1/7)+.+(1/97-1/100)]=(1-1/100)/3=33/100
2.13又七分之1
整数分数分别相加=13+1/10+1/40+1/88+1/154=13+1/8+1/88+1/154=13+3/22+1/154=13+1/7
3.1002
整数分数分别相加减=1*2004-(1/2005+2/2005+.+2004/2005)
=2004-2004*(1/2005+2004/2005)/2=2004-1002=1002