The answer is (7x + 5)(7x - 5).
Since the equation is a difference of two squares, then the answer'll be in the format (ax - b)(ax + b), where the equation is a^2 x^2 - b^2
[tex]49x^{2}-25\\\\\sqrt{a^{2}}=\sqrt{49}=\pm7\\\sqrt{b^{2}}=\sqrt{25}=\pm5\\\\(ax+b)(ax-b)\\\\(7x+5)(7x-5)[/tex]