Question

(5m^2)(–n) + (–3m^2)(–4n)

Answer 1

Make the 2 terms into like terms
Basically add the "-n" nu multiply
\[\huge~\rm~\bf −5m^2n+12m^2n\]
From here just combine like terms

Answer 2

ignore all the letters focus on the numbers
\[\huge~\rm~-5+12=?\]

Answer 3

7

Answer 4

Good now just add the ending (the letters)
what do you get?

Answer 5

7m^2n

Answer 6

Well done =)