(1\2+1\3)+(2\3+1\4)+(3\4+1\5)+(4\5+1\6)+.+(18\19+1\20)+(19\2
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/08/18 13:54:52
(1\2+1\3)+(2\3+1\4)+(3\4+1\5)+(4\5+1\6)+.+(18\19+1\20)+(19\20+1\2)
![(1\2+1\3)+(2\3+1\4)+(3\4+1\5)+(4\5+1\6)+.+(18\19+1\20)+(19\2](/uploads/image/z/9971336-56-6.jpg?t=%281%5C2%2B1%5C3%29%2B%282%5C3%2B1%5C4%29%2B%283%5C4%2B1%5C5%29%2B%284%5C5%2B1%5C6%29%2B.%2B%2818%5C19%2B1%5C20%29%2B%2819%5C2)
去掉括号,得到
1/2+1/3+2/3+1/4+3/4+1/5+4/5+…+1/19+18/19+1/20+19/20+1/2
=1/2+(1/3+2/3)+(1/4+3/4)+1/5+4/5)+…+(1/19+18/19)+(1/20+19/20)+1/2
=1/2+1+1+1+…+1+1+1/2
=19
1/2+1/3+2/3+1/4+3/4+1/5+4/5+…+1/19+18/19+1/20+19/20+1/2
=1/2+(1/3+2/3)+(1/4+3/4)+1/5+4/5)+…+(1/19+18/19)+(1/20+19/20)+1/2
=1/2+1+1+1+…+1+1+1/2
=19
求1/2*3+1/3*4+1/4*5+.+1/18*19+1/19*20
1/2×3+1/3×4+1/4×5+.+1/18×19+1/19×20等于?
简算1/2*3+1/3*4+1/4*5+.+1/18*19+1/19*20
1/2*3+1/3*4+1/4*5+.+1/18*19+1/19*20=?
1/1*2*3+1/2*3*4+1/3*4*5+.+1/18*19*20
(1\2+1\3)+(2\3+1\4)+(3\4+1\5)+(4\5+1\6)+.+(18\19+1\20)+(19\2
1/1*2*3*4+1/2*3*4*5+1/3*4*5*6.+1/17*18*19*20
2/1*2*3+2/2*3*4+2/3*4*5+...+2/18*19*20
1+2+3+4+5+…+18+19+20=
1/1*3+1/2*4+1/3*5+1/4*6+1/5*7+1/6*8------1/17*19+1/18*20 如何用
1/1*3+1/2*4+1/3*5+1/4*6+1/5*7+1/6*8------1/17*19+1/18*20 怎样做
1/1*3+1/2*4+1/3*5+1/4*6+1/5*7+1/6*8------1/17*19+1/18*20