Answer:
We first register the purchase of the patent:
Account          Debit      Credit
Cash                      $46,000
Patent         $46,000
Now we register the amortization for the first year. Because the useful life is 10 years, then, each year the patent will lose $4,600 of its value ($46,000 / 10 = $4,600)
Account          Debit       Credit
Amortization      $4,600
Patent                     $4,600