Chapter R - Section R.4 - Factoring Polynomials - R.4 Exercises - Page 40: 100

$(10r+13s)(10r-13s)$

Using $a^2-b^2=(a+b)(a-b)$ or the factoring of the difference of two squares, then the factored form of the expression, $ 100r^2-169s^2 ,$ is \begin{array}{l}\require{cancel} (10r+13s)(10r-13s) .\end{array}