Answer: $30,000
Explanation:
Amortization from September 1, 2019 - January 1, 2021 :
September 1, - december 31 = 4/12 = 0.333333
(1 + 0.333333) × (135000 × 10) = $18,000
Value left before patent defense :
$(135,000 - 18,000) = $117,000
Amount reported for patent amortization expense 2021:
$(117,000 + 33,000) ÷ 5
$150,000 ÷ 5 = $30,000