What is 1/2 + 9/10 + m + n=2?

If you would like to solve the equation 1/2 + 9/10 + m + n = 2, you can do this using the following steps:

1/2 + 9/10 + m + n = 2
m + n = 2 - 1/2 - 9/10
m + n = 20/10 - 5/10 - 9/10
m + n = 6/10
m + n = 3/5

If you want to solve this equation for m:
m = 3/5 - n

If you want to solve it for n:
n = 3/5 - m