Type out the journal entries for the following transactions.

1. The business received $1200 cash when a customer paid their invoice two weeks after the service was performed.

2. Darwin invested $15,000 in a business, which in turn issued common stock to him.

3. The business provided services totaling $850 to a customer and allowed the customer to pay at the end of the month.

4. The business paid cash for supplies, $100.