Answer:
The numbers are 1/2 and 17/2
Step-by-step explanation:
Let the two numbers be represented by a and b.
Given that
Their sum is 9, we have:
a + b = 9 ......................................................................................(1)
Their difference is -8, then
a - b = -8 .......................................................................................(2)
To know the values of the numbers a and b, we need to solve the equations (1) and (2) simultaneously.
From (2)
a = b - 8 .......................................................................................(3)
Using equation (3) in (1)
b - 8 + b = 9
2b - 8 = 9
Add 8 to both sides
2b - 8 + 8 = 9 + 8
2b = 17
Divide both sides by 2
b = 17/2 ......................................................................................(4)
Using (4) in (3)
a = 17/2 - 8
a = 1/2