What is the sum of the polynomials (m+n+3) (m+n+4)

(m + n + 3) (m + n + 4)

First distribute the m in the first set of parentheses to the second set of parentheses. Do the same process with the n and the 3.

m^2 + mn + 4m + mn + n^2 + 4n + 3m + 3n + 12

Combine Like terms. Final Answer:

m^2 + n^2 + 2mn + 7m + 7n + 12