The average of m, n, and -1 is 0. what is the value of m+n?

1

Explanation:

To average a bunch of numbers, we add them up and divide by how many numbers there are. In this case, we'll divide by 3 since there are 3 numbers.

Add up the values: m+n+(-1) = m+n-1

Divide by 3: (m+n-1)/3

Set this equal to 0 since we're told the average is 0: (m+n-1)/3 = 0

Now let's isolate m+n. It might help to replace "m+n" with another variable, say P to get (P-1)/3 = 0.

Solve for P

(P-1)/3 = 0

P-1 = 3*0 multiply both sides by 3

P-1 = 0

P = 1 ... add 1 to both sides

m+n = 1 replace P with m+n

So that's why the answer is 1