8m - n = p
Add n to both sides:
8m = n + p
Add m to both sides:
9m = n + p + m
Now, divide both sides by 3
3m = (n + p + m)/3 = the average of n, p, and m
If 8m − n = p, then which of the following represents the average (arithmetic mean) of m, n, and p, in terms of m?
1) 2m −1
2) 3m
3) 6m
4) m/5
5) 6m/5