My question reads 8000 in roth ira contributions were made for the year... is roth ira
An adjustment and subtracted in my problem early on, OR subtracted as a credit towards the end?

Roth IRA contributions aren't deductible for tax. There is a credit that might be taken directly off taxes that comes from doing several different types of retirement accounts, which is a different thing.

However... I have no idea what you are referring to with your "problem early on" or "credit towards the end."