\(x-\dfrac{1}{2}-\dfrac{1}{2.3}-\dfrac{1}{3.4}-\dfrac{1}{4.5}-...-\dfrac{1}{2021.2022}-\dfrac{1}{2022.2023}=\dfrac{-2024}{2023}\)
Tính nhanh A = 1/1.2 + 1/2.3 + 1/3.4 + 1/3.4 + ... + 1/49.50
1/1.2+1/2.3+1/3.4+...+1/99.100
1/1.2+1/2.3+1/3.4+…+1/2021.2022
(1/1.2+1/2.3+1/3.4+...+1/6.9
cho A = 1/1.2+1/2.3+1/3.4+...+1/49.50 ; cho B = 1.2+1.3+3.4+....+49.50
tính 50mủ 2A - B/17
1/1.2+1/2.3+1/3.4+...+1/59.60= /60
Tính :
1/1.2 + 1/2.3 + 1/3.4 + . . . + 1/99.100
Chứng tỏ rằng: 1/1 - 1/2 =1/1.2 ; 1/2 -1/3 = 1/2.3 ; 1/3 -1/4 =1/3.4
Tính S = 1/1.2 + 1/2.3 + 1/3.4+... 1/49.50
Tính: A= 1 - 1/1.2 - 1/2.3 - 1/3.4 - ...- 1/97.98