Explanation:
The journal entry is as follows
Amortization expense Dr $2.5 million
To Patent $2.5 million
(Being the amortization expense is recorded)
The computation is shown below:
The annual amortization is
= $9 million ÷ 9 years
= $1 million
So, the amortization for four years from 2017 to 2021 is $4 million
Now the unamortized value is
= $9 million - $4 million
= $5 million
And, the remaining life is 2 years (6 years - 4 years)
So, the amortization expense is
= $5 million ÷ 2 years
= $2.5 million