Some of the Following Errors Would Cause the Debit and Credit

Some of the following errors would cause the debit and credit columns of the trial balance to have unequal totals.
1. A payment of $700 to a creditor was recorded by a debit to Accounts Payable of $70 and a credit to Cash of $700.
2. A $340 payment for a printer was recorded by a debit to Computer Equipment of $34 and a credit to Cash for $34.
3. An account receivable in the amount of $2,000 was collected in full. The collection was recorded by a debit to Cash for $2,000 and a debit to Accounts Payable for $2,000.
4. An account payable was paid by issuing a cheque for $800. The payment was recorded by a debit to Accounts Payable $800 and a credit to Accounts Receivable $800.
Instructions
For each of the four cases, state whether the error would cause unequal totals in the trial balance. If the error causes unequal totals, indicate the amount of difference between the columns and state whether the debit or credit is larger. Each case is to be considered independently of the others.