I notice that in all four cases, that the second number is even.

input #1   Input #2    Output
   5          4          17
   6          8          22
   2          8          10
   9          6           ?

What we can do with even numbers, that we can't do with odd numbers,
is to take half of them and get a whole number.  So let's take half
of them and see if that helps:

            Half of
input #1   Input #2   Output
   5          2          17
   6          4          22
   2          4          10
   9          3           ?

Aha, I see that if I subtract half of input #2 from the output number,
I always get 3 times input #1.  So the simplest pattern is:

Multiply input #1 by 3 
Take half of the second input
Add them together.

That works in the first 3 cases:

So to find the answer to the fourth case:

Multiply 9 by 3, get 27 
Take half of the second input 6, get 3
Add them together, 27+3 = 30.

Edwin