1949²-1950²+1951²-1952²+……+1997²-1998²+1999²
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/18 23:48:52
![1949²-1950²+1951²-1952²+……+1997²-1998²+1999²](/uploads/image/z/176237-53-7.jpg?t=1949%26%23178%3B-1950%26%23178%3B%2B1951%26%23178%3B-1952%26%23178%3B%2B%E2%80%A6%E2%80%A6%2B1997%26%23178%3B-1998%26%23178%3B%2B1999%26%23178%3B)
xP
0C-:!u,BwPpEӰ@W NT*JQS8 yC
ią~tTEu5(^&8%TӻQ`_t`)Yx ʓ5?W}kңdZv84J#}L} ?!-
1949²-1950²+1951²-1952²+……+1997²-1998²+1999²
1949²-1950²+1951²-1952²+……+1997²-1998²+1999²
1949²-1950²+1951²-1952²+……+1997²-1998²+1999²
=(1999-1998)*(1999+1998)+(1997-1996)*(1997+1996)+...+(1951-1950)*(1951+1950)+1949*1949
=1999+1998+1997+.+1950+1949*1949
=(1999+1950)*25+1949*1949
=3949*25+1949*1949
=98725+3798601
=3897326