lilybaxter2016 lilybaxter2016 15-02-2018 Mathematics contestada Find the sum of the given polynomials. 5 m + 2 n , n - 3 m , and 7 - 3 n A. 7 - 2 m B. 2 m + 7 C. 14 m + 5 n - 6 D. 9 m