Question

CMR: \(\frac{1}{n}+\frac{1}{n+1}=\frac{1}{n\left(n+1\right)}\)

Answer 1

viết sai đề rồi phải là

CMR: \(\frac{1}{n}-\frac{1}{n+1}=\frac{1}{n\left(n+1\right)}\)

Answer 2

\(\frac{1}{n}-\frac{1}{n+1}=\frac{1}{n+1}\)

\(\frac{1}{n}-\frac{1}{n-1}\)

=\(\frac{1.\left(n+1\right)}{n.\left(n+1\right)}-\frac{1.n}{n\left(n+1\right)}\)

=\(\frac{1}{n.\left(n+1\right)}\)

Answer 3

biet giai roi ma dang chi cho sai de