Question

b1 :tính

a) N = (1/2 - 1). (1/3 - 1). (1/4 - 1) .... (1/2016 - 1). (1/2017 - 1)

b) P = (-1/1/2). (-1/1/3). (-1/1/4) ... (-1/1/2015). (2016/01/01)

c) Q = 1/13 + 3 / 13,23 + 3 / 23,33 + ... + 3 / 2013,2023

d) R = 1 / 2.017,2016-1 / 2.016,2015-1 / 2015,2014 - ... -. 1 / (x + 1999) (x + 2000)

b2 : tìm x, biết :

a) 1 / (x + 1). (x + 2) + 1 / (x + 2). (x + 3) + 1 / (x + 3). (x + 4) + ... + 1 / (x + 1999). (x + 2000) = 1 / x + 200 = 1/5

b) 2 / (x + 1). (x + 3) + 3 / (x + 3). (x + 6) + 4 / (x + 6). (x + 10) + ... + 10 / (x + 45). (x + 55) + 1 / x + 55 = 1/6

( chú ý : / là phần nha )

Answer 1

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