Math
posted by B.B. .
Can someone please explain this to me: Does n+m=n + m for all integers n and m? If so, give some examples. If not, give a counterexample.

Simply substitute numbers of opposing signs for n+m.
For example, n=1, and m = 2
n+m = 1+2 = 1 = 1
n + m = 1 + 2 = 1+2=3