Let's look at the information that you do have.
y = yellow
g = green
g + y = 38
g = 38 - y
If there are 14 green skittles,then we know that:
14 + y = 38
14 = 38 - y
so, we can then do the equation:
38 - 14 = y
38 - 14 = 24
y = 24
So, the answer is 24 green skittles.
