if we consider a variable y which is some number we don’t yet know. We can say that we have y apples. If y=5 we have 5 apples. However, in this case we have y= 14 plus 2 times a number. This relationship can be described by introducing another variable x (some number we dont yet know) for the number we need to multiply by 2, we get y=14+2x.
the answer should be 14+2x or y=14+2x.
if you meant instead the sum of 14 and twice a number over a range of values for that number. The answer should be sigma for i=(range) of 14+2x