The journal entry to record the issuance of the note is:
Debit: Cash = $51,000 (proceeds received)
Debit: Discount on Note Payable = $787 (computed as $51,000 x 7% x 90/360)
Credit: Notes Payable = $51,787 (face value of the note)
The entry can be summarized as:
Debit: Cash $51,000
Debit: Discount on Note Payable $787
Credit: Notes Payable $51,787