Write 2 equations:
a +b = 39
and b = 1/2a + 6
Now replace b in the first equation with the second one:
a + 1/2a + 6 = 39
Combine like terms:
1 1/2a + 6 = 39
Subtract 6 from each side:
1 1/2a = 33
Divide both sides by 1 1/2:
a = 33 / 1 1/2 = 33 / 1.5
a = 22
Now replace a with 22 in the first equation and solve for b:
22 + b = 39
b = 39 -22
b = 17
The two numbers are 17 and 22.
