Answer:
<h2>Sage Learning Centers</h2>
1A. Single-Column Revenue Journal:
July 21 J. Dunlop $115
July 22 K. Tisdale $350
July 24 T. Quinn  $85
July 25 K. Tisdale $300
July 27 F. Mintz $225
July 30 D. Chase $170
July 30 K. Tisdale $120
July 31 T. Quinn $105
Accounts Receivable $1,470
Being summary of customers account for the month of July.
1B. General Journal
Debit     Description                    Debit              Credit
July 25  Supplies                       $300
               Accounts Receivable (K. Tisdale)      $300
To record the exchange of educational supplies for services.
July 31   Accounts Receivable      $1,470
              Fees Earned                                      $1,470
To record the Fees Earned during July.  
1C.   Accounts Receivable Ledger:
J. Dunlop's Account
Date     Description                        Debit      Credit    Balance
July 21  Accounts Receivable        $115                       $115
K. Tisdale's Account
Date     Description                         Debit      Credit      Balance
July 22  Accounts Receivable        $350                       $350
July 27  Accounts Receivable        $300                       $650
July 27  Supplies                                            $300        $350
July 30  Accounts Receivable        $120                       $470
T. Quinn's Account
Date     Description                         Debit      Credit    Balance
July 24  Accounts Receivable        $85                       $85
July 31   Accounts Receivable      $105                      $190
F. Mintz's Account
Date     Description                        Debit      Credit    Balance
July 27  Accounts Receivable       $225                       $225
D. Chase's Account
Date     Description                         Debit      Credit    Balance
July 30  Accounts Receivable        $170                       $170
2. General Ledger
12 Accounts Receivable
Date     Description                         Debit      Credit    Balance
July 25 Supplies                                            $300     ($300)
July 31  Fees Earned                   $1,470                     $1,170
13 Supplies Account
Date     Description                         Debit      Credit    Balance
July 25 Accounts Receivable         $300                     $300
41 Fees Earned Account
Date     Description                         Debit      Credit    Balance
July 31  Accounts Receivable                        $1,470   $1,470
3A. The sum of the balances of the customer accounts in the subsidiary ledger at July 31 is $1,170.
3B.  The balance of the accounts receivable controlling account at July 31 is $1,170.
Explanation:
Journals are important prime books of original entry.  They record business transactions as they occur.  Some are used as memorandum records to accumulate the total for the period, like the Revenue or Sales Journal.  Others show the accounts to be debited and the ones to be credited in the general ledger.