1×2×3+2×3×4+3×4×5+…+n(n+1)(n+2)=?

来源：学生作业帮助网编辑：六六作业网时间：2024/11/24 01:45:05

1×2×3+2×3×4+3×4×5+…+n(n+1)(n+2)=?1×2×3+2×3×4+3×4×5+…+n(n+1)(n+2)=?1×2×3+2×3×4+3×4×5+…+n(n+1)(n+2)=?1

1×2×3+2×3×4+3×4×5+…+n(n+1)(n+2)=?
1×2×3+2×3×4+3×4×5+…+n(n+1)(n+2)=?

1×2×3+2×3×4+3×4×5+…+n(n+1)(n+2)=?
1×2×3+2×3×4+3×4×5+.+n(n+1)(n+2)
=1/4【1×2×3×4-0×1×2×3】+1/4【2×3×4×5-1×2×3×4】+1/4【3×4×5×6-2×3×4×5】+.+
1/4【n(n+1)(n+2)（n+3)-(n-1)n(n+1)(n+2)】
=1/4n(n+1)(n+2)(n+3)
希望对你能有所帮助.

1*2*3=1/4(1*2*3*(4-0)
2*3*4=1/4(2*3*4*(5-1)
......
n*(n+1)*(n+2)=1/4*n*(n+1)*(n+2)[n+3-(n-1)]
Sn=1*2*3+2*3*4+3*4*5+...+n*(n+1)*(n+2)
=1/4{1*2*3*(4-0)+2*3*4*(5-1)+3*4*5*(6-2)...+n*...

全部展开

1*2*3=1/4(1*2*3*(4-0)
2*3*4=1/4(2*3*4*(5-1)
......
n*(n+1)*(n+2)=1/4*n*(n+1)*(n+2)[n+3-(n-1)]
Sn=1*2*3+2*3*4+3*4*5+...+n*(n+1)*(n+2)
=1/4{1*2*3*(4-0)+2*3*4*(5-1)+3*4*5*(6-2)...+n*(n+1)*(n+2)[n+3-(n-1)]}
=1/4{1*2*3*4+2*3*4*5-1*2*3*4+3*4*5*6-2*3*4*5+..........+n*(n+1)(n+2)(n+3)-(n-1)*n(n+1)(n+2)}原式= n*(n+1)*(n+2）*（n+3）/4

收起

1+2+3+4+5…………+100000000 (1/3+2/3)+(1/4+2/4+3/4)+(1/5+2/5+3/5+4/5)+……(1/100+……+9/100) 计算：1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+3/5+4/5+……+1/6+…+59/60 c++编程:1*1+2*2+3*3+4*4+5*4……+n*n 1+2+3+4+5+………+9999+10000+9999+………+5+4+3+2+1=? 有一列数,1,2,2,3,3,3,4,4,4,4,5,5,5,5,5,………………第200个数是多少? 1×2×3+2×3×4+3×4×5……+7×8×9 简算? (3+1)(3^2+1)(3^3+1)(3^4+1)(3^5+1)……(3^32+1) 1×2×3+2×3×4+3×4×5+…+n(n+1)(n+2)=? 1+1+2+3+4+5+……= 1+2+3+4+5+6……………………+100000000=? 1*3+3*3^2+5*3^3+7*3^4+……+（2n-1）*3n 5+5/1×2+5/2×3+5/3×4+……5/99×100 1×2+2×3+3×4+4×5+5×6+……+19×20 1+2+2+3+3+4+4+5+5……+999+999+1000+1000= (1-2)(2-3)(3-4)(4-5)(5-6)……(2008-2009)(2009-2010) 3*4+3*4^2+3*4^3+3*4^4+3*4^5+……+3*4^（n-1）等于多少 1+1×2+1×2×3+1×2×3×4+1×2×3×4×5+……+1×2×3……×99×100 这个算式的