解题:1X2+2X3+3X4+……+100X101
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/06 18:05:19
![解题:1X2+2X3+3X4+……+100X101](/uploads/image/z/1025934-6-4.jpg?t=%E8%A7%A3%E9%A2%98%EF%BC%9A1X2%2B2X3%2B3X4%2B%E2%80%A6%E2%80%A6%2B100X101)
解题:1X2+2X3+3X4+……+100X101
解题:1X2+2X3+3X4+……+100X101
解题:1X2+2X3+3X4+……+100X101
=1/3*1*2*3+1/3[2*3*4-1*2*3]+1/3[3*4*5-2*3*4]+.+1/3[100*101*102-99*100*101]
=1/3[1*2*3+2*3*4-1*2*3+3*4*5-2*3*4+...+100*101*102-99*100*101]
=1/3*100*101*102
=343400