Answer:
22.5 and 13.5 are the numbers. average of both numbers is 18.
Explanation:
Given that there are two numbers.
let them be, x and y
using the unknown numbers,
make x the subject:
- x + y = 36
- x = 36 - y ..........equation 1
- x - y = 9
- x = 9 + y ..........equation 2
Solve them simultaneously:
- 9 + y = 36 - y
- y + y = 36 - 9
- 2y = 27
- y = 13.5
Then another number, x:
- x = 9 + y
- x = 9 + 13.5
- x =22.5
Average:
- ( sum of both the numbers ) ÷ 2
- ( 22.5 + 13.5 ) ÷ 2
- 18