The following are independent errors. Prepare correcting journal if needed for each the following errors (ignore income taxes)

1. In January 2016, repair costs of $9,000 were debited to the Machinery account. At the beginning of 2016, the book value of the machinery was $100,000. No residual value is expected, the remaining estimated life is 10 years, and straight-line depreciation is used.
2. Equipment with a book value of $70,000 and a fair value of $100,000 was sold at the beginning of the year. A 2-year, non-interest-bearing note for $129,960 was received and recorded at its face value, and a gain of $59,960 was recognized. No interest revenue was recorded and 14% is a fair rate of interest.
3. Payment of next years rent, $5000, was recorded as rent expense
4. Allowance for the doubtful accounts of $5,000 was not recorded. The company uses aging method (percentage of receivable method). The error was discovered after the accrual for uncollectible accounts is made at the end of the following year.