Answer:
Explanation:
Comment
If 4 numbers have an average of 9, then total of the 4 numbers is 4 * 9 = 36.
If one of the 4 numbers is a 7, then
7 + x = 36 where x is the sum of the other 3 numbers.
7 + x = 36 Subtract 7 from both sides
7- 7 +x = 36 - 7
x = 29
Answer 29