In your notebook, set up the following addition using a vertical format and find the sum of the given polynomials.

2mn + 4n^2 and 5m^2 - 7mn

a. 9m^2 + 9mn - 4n^2
b. 5m^2 - 14mn - 4n^2
c. 5m^2 - 5mn + 4n^2
d. 5m^2 + 5mn - 4n^2

i need to know how to do it and the answer. any number following a ^ is an exponent.