Question

Bài 10:Tính

g,A=\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+....+\(\dfrac{1}{49.50}\)

Answer 1

A = 1/1 - 1/2 + 1/2 - 1/3 + ... + 1/49 - 1/50

A = 1/1 - 1/50

A = 49/50

Answer 2

\(A=\dfrac{1}{1\cdot2}+\dfrac{1}{2\cdot3}+...+\dfrac{1}{49\cdot50}\)

\(A=1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+...+\dfrac{1}{49}-\dfrac{1}{50}\)

\(A=1-\dfrac{1}{50}\)

\(A=\dfrac{49}{50}\)

Answer 3

\(A=\dfrac{1}{1}-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+...+\dfrac{1}{49}-\dfrac{1}{50}\)

\(A=1-\dfrac{1}{50}\)

\(A=\dfrac{49}{50}\)