Answer:
2mn+4n^2 and 5m^2-7mn
Step-by-step explanation:
The steps to follow to carry out this operation is to bring together those who are equal: 2mn + 4n ^ 2 and 5m ^ 2-7mn
We have: 2mn and -7mn
Therefore: 5m ^ 2 + (2-7) mn + 4n ^ 2
What will result in: 5m ^ 2 - 5mn + 4n ^ 2
