I have tried to use abel's test and solve as following
Take sequence ${b_n(x)}$ as $\frac{-1^n}{n}$ which is uniformally convergent by Lebinitz test. Also $\frac{x^n}{x^n+1}$ = $\frac{1+x^n-1}{1+x^n}$ = $1 - \frac{1}{1+x^n}$ but this is not monotonic decreasing for a particular value of $x$. How to proceed further?