1x2x3+2x3x4+3x4x5+…+8x9x10

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/02 06:22:19

1×2×3+2×3×4+3×4×5+……+8×9×10
=(1/4)(1×2×3×4)+(1/4)(2×3×4×5-1×2×3×4)+(1/4)(3×4×5×6-2×3×4×5)+……(1/4)(8×9×10×11-7×8×9×10)
=(1/4)(1×2×3×4+2×3×4×5-1×2×3×4+3×4×5×6-2×3×4×5+……+8×9×10×11-7×8×9×10)
=(1/4)(8×9×10×11)
=2×9×10×11
=1980

1x2x3+2x3x4+3x4x5+…+8x9x10 1/1x2x3+1/2x3x4+1/3x4x5+1/4x5x6+...+1/8x9x10 等于多少? 1x2X3+2x3X4+3x4X5+…+7X8X9=? 1/1x2x3+1/2x3x4+1/3x4x5 1x2x3+2x3x4+3x4x5+...+7x8x9=, 1x2x3+2x3x4+3x4x5+.+10x11x12 1x2x3+2x3x4+3x4x5……+10x11x12巧算请在两天之内回答 1/2x3X4十1/3X4x5十1/4X5X6……十1/8X9X10等于多少最好给个详细答案谢谢数学简便计算1/1x2x3+1/2x3x4+1/3x4x5……+1/20x21x22=? 1/1x2x3+1/2x3x4+1/3x4x5+1/4x5x6+.+1/48x49x50= 1/1x2x3+1/2x3x4+1/3x4x5+.+1/11x12x13= 1/1x2x3+1/2x3x4+1/3x4x5+.+1/9x10x11=