4+6+...+20+1-3-5-...-19=
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:2024/06/30 12:13:56
4+6+...+20+1-3-5-...-19=
199+299+399+499+599+5=
99999x22222+33333x33334=
591x482+118=
199+299+399+499+599+5=
99999x22222+33333x33334=
591x482+118=
199+199+100+199+200+199+300+199+400+5
=(199×5+5)+(100+200+300+400)
=(199+1)×5+1000
=1000+1000
(199+1)+(299+1)+(399+1)+(499+1)+(599+1)
33333X3X22222+33333X33334
=33333X(3×22222+33334)
=33333X(66666+33334)
=33333X100000
591X482+600-482
=591X482-482+600
=590x482+600
=(600-10)X482+600
=600X482-10X482+600
=600X483-4820
=289800-4820
591X482+118
=591X(600-118)+118
=591X600-591X118+118
=591X600-590X118
=591×600-(600-10)X118
=591X600-600X118+118×10
=(591-118)x600+1180
=473x600+1180
=283800+1180
=(199×5+5)+(100+200+300+400)
=(199+1)×5+1000
=1000+1000
(199+1)+(299+1)+(399+1)+(499+1)+(599+1)
33333X3X22222+33333X33334
=33333X(3×22222+33334)
=33333X(66666+33334)
=33333X100000
591X482+600-482
=591X482-482+600
=590x482+600
=(600-10)X482+600
=600X482-10X482+600
=600X483-4820
=289800-4820
591X482+118
=591X(600-118)+118
=591X600-591X118+118
=591X600-590X118
=591×600-(600-10)X118
=591X600-600X118+118×10
=(591-118)x600+1180
=473x600+1180
=283800+1180
4+6+...+20+1-3-5-...-19=
3/19+4/19+5/19+6/19+...+19/19+20/19+21/19=?
1*3+2*4+3*5+4*6+``````19*21+20*22=
1*2*3*4+2*3*4*5+3*4*5*6+.+17*18*19*20=?
1/2*3+1/3*4+1/4*5+.+1/18*19+1/19*20=?
动动脑,巧算3/19+4/19+5/19+6/19+.+19/19+20/19+21/19
简算3/19+4/19+5/19+6/19+...+19/19+20/19+21/19
1-2+3-4+5-6~~+19-20+21
1-2+3-4+5-6+……+19-20+21=?
1+2+3+4+5+…+18+19+20=
1/(1*2*3*4)+1/(2*3*4*5)+1/(3*4*5*6)+.+1/(17+18+19+20)=?
3/(1*2*3*4)+3/(2*3*4*5)+3/(3*4*5*6)+...+3/(17*18*19*20)=