#### Answer

(3m+10)(3m-10)

#### Work Step by Step

9m$^2$-100
This polynomial is a difference of squares. If a is the square root of the first term and b is the square root of the second term, then the factorization is (a+b)(a-b).
$\sqrt {9m^2}$=3m and
$\sqrt {100}$=10. So
(3m+10)(3m-10).