Question

tính tổng:

1/2x3+1/3x4+....+1/49x50

nhanh lên nha mk sắp thi rồi nhớ tính cụ thể nha

Answer 1

\(\Rightarrow\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+.......+\frac{1}{49}-\frac{1}{50}.\)

=>1/2-1/50=25/50-1/50=24/50=12/25

Answer 2

`1/(2xx3)+1/(3xx4)+....+1/(49xx50)`

`=1/2-1/3+1/3-1/4+....+1/49-1/50`

`=1/2-1/50`

`=25/50-1/50`

`=24/50`

`=12/25`