Notified Alex's Engineering Co. That business solutions' bid of 7000 on a proposed project has been accepted. Alex's paid 1500 cash advance to business solution.

For Business Solution the journal entry will be:
Debit Cash for $1,500
Credit Unearned Revenue for $1,500

For Alex the journal entry will be:
Debit an appropriate Expense account for $1,500
Credit Cash for $1,500