Answer
$\color{blue}{(7x+\frac{1}{5})(7x-\frac{1}{5})}$
Work Step by Step
With $49x^2=(7x)^2$ and $\frac{1}{25}=(\frac{1}{5})^2$, the given binomial is equivalent to:
$=(7x)^2-(\frac{1}{5})^2$
Factor using the formula $a^2-b^2=(a+b)(a-b)$ with $a=7x$ and $b=\frac{1}{5}$ to obtain:
$=\color{blue}{(7x+\frac{1}{5})(7x-\frac{1}{5})}$