Question

A=1/1*2 + 1/2*3 + 1/3*4 +...+1/2015*2016

Answer 1

\(A=\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+..+\frac{1}{2015.2016}=\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2015}-\frac{1}{2016}\)
\(=\frac{1}{1}-\frac{1}{2016}=\frac{2016}{2016}-\frac{1}{2016}=\frac{2015}{2016}\)

vậy A=2015/2016

Answer 2

\(A=\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+...+\frac{1}{2015\cdot2016}=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{2015}-\frac{1}{2016}\)

\(=\left(1-\frac{1}{2016}\right)+\left(\frac{1}{2}-\frac{1}{2}\right)+\left(\frac{1}{3}-\frac{1}{3}\right)+...+\left(\frac{1}{2015}-\frac{1}{2015}\right)\)

\(=\left(\frac{2016}{2016}-\frac{1}{2016}\right)+0+...+0=\frac{2015}{2016}\)

Answer 3

A=1+1/2016=bao nhiêu tự tính

Answer 4

A= \(\frac{2015}{2016}\)

Answer 5

\(\frac{2015}{2016}\)