Question 1 (1-1 / 2) (1 / 3-1) (1-1 / 4) (1 / 5-1)... (1 / 2013-1) (1-1 / 2014) question 2 (1 / 9-1 / 8-3 / 16) * 48-35.75 * 2 4 / 5+（ Question 1 (1-1 / 2) (1 / 3-1) (1-1 / 4) (1 / 5-1)... (1 / 2013-1) (1-1 / 2014) question 2 (1 / 9-1 / 8-3 / 16) * 48-35.75 * 2 and 4 / 5 + (- 25 and 1 / 4) * (- 2 and 4 / 5) + 4.5 * (- 2 and 4 / 5)

Question 1 (1-1 / 2) (1 / 3-1) (1-1 / 4) (1 / 5-1)... (1 / 2013-1) (1-1 / 2014) question 2 (1 / 9-1 / 8-3 / 16) * 48-35.75 * 2 4 / 5+（ Question 1 (1-1 / 2) (1 / 3-1) (1-1 / 4) (1 / 5-1)... (1 / 2013-1) (1-1 / 2014) question 2 (1 / 9-1 / 8-3 / 16) * 48-35.75 * 2 and 4 / 5 + (- 25 and 1 / 4) * (- 2 and 4 / 5) + 4.5 * (- 2 and 4 / 5)

1 / 2 * (- 2 / 3) * (3 / 4) * (- 4 / 5)... * (- 2012 / 2013) * 2013 / 2014, see if there are any rules? Ah, yes, all of them are eliminated. Except for 1007 - 1, so the answer is - 1 / 2014. Second, you can find the rules, put the long ones together, and you can quickly calculate them

Teacher Li gave the students a question: when x = 2014, y = 2013
Li Hua gave the students a question: when x = 2014, y = 2013, find the value of [2x (x2y-xy2) + XY (2xy-x2)] / X2Y. After the question was finished, Xiao Ming said: "the condition given by the teacher, y = 2006, is redundant." Wang Guang said: "if you don't give this condition, you can't find the result, so it's not redundant." who do you think makes sense? Why?

[2x（x²y-xy²）+xy（2xy-x²）]÷x²y
=[2x²y(x-y)+x²y(2y-x)]/x²y
=2(x-y)+2y-x
=2x-2y+2y-x
=x
So the result of the original formula has nothing to do with y, so Xiao Ming is right