The following are independent errors:

a$.$ In January $2019,$ repair costs of $$10,320$ were debited to the Machinery account. At the beginning of $2019,$ the book value of the machinery was $$85,800.$ No residual value is expected, the remaining estimated life is $10$ years, and straight$-$line depreciation is used.

b$.$ All purchases of materials for construction contracts still in progress have been immediately expensed. It is discovered that the use of these materials was $$9,560$ during $2018$ and $$12,370$ during $2019.$

c$.$ Depreciation on manufacturing equipment has been excluded from manufacturing costs and treated as a period expense. During $2019,$ $$44,500$ of depreciation was accounted for in that manner. Production was $14,800$ units during $2019,$ of which $1,480$ remained in inventory at the end of the year. Assume there was no inventory at the beginning of $2019.$

Required:

Prepare journal entries for the preceding errors discovered during $2020.$ Ignore income taxes.