What is the simplified form of the following expression?

7m^2 + 6.5n - 4 + 2.5m^2 - n

A. 9.5m^2 + 1.5n
B. 4.5m^2 + 1.5n
C. 1.5m^2 - 4.2n
D. 9.5m^2 -1.5n***** <-- The one I chose.

I did this and got 9.5m^2 and 2.5n. Was I supposed to make the n a 1 and subtract it from 2.5n? And the operation symbol is supposed to be subtraction between the two answers right?

1 answer

How?