Differed tax asset

CFA Level I FRA
#1

For Research & Development:

If at the beginning $75K is expensed as R&D expense.

And at the first year tax base is $50K (75K-25K accumulated tax amortization) and asset has no carrying value.

Now why in this case amortization leads to a deferred tax? how is earning before tax less than taxable income?

#2

I don’t quite understand the situation. Is this a question from the curriculum? If so, I can look at the details and, perhaps, give you a helpful answer.