Answer:
8 and 9.
Explanation:
Let the two unknown numbers be a and b.
When added together, they equal 17. In other words:
a + b = 17.
The difference between five times the first number and three times the second number is 13. In other words:
5a - 3b = 13.
We have a system of equations. We can use substitution. From the first equation, we can derive a = 17 - b. Let's substitute this in:
5(17 - b) - 3b = 13
85 - 5b - 3b = 13
-8b = -72
b = 9
a = 17 - b.
a = 17 - 9 = 8.
Thus, the two numbers are 8 and 9.