Answer and Explanation:
1. 
Net Operating loss carryback  Amount  Rate of Tax  Tax	Recorded as
Carried back - 2014               $0.0          30%         $0.0  
Carried back - 2015               $0.0          30%         $0.0  
Carried back - 2016           $42,000        35%	$14,700.0  
Carried back - 2017           $8,000.0       40%	$3,200.0  
Total Carryback                 $50,000.0                    $17,900.0	
Journal Entries - Cabot Company
Date                Particulars                                  Debit	Credit
31-Dec-18      Receivables - Income Tax Refund  $17,900
           To Income tax benefit - Net Operating Loss           $17,900  	
2. Cabot's net loss for 2018 = -$50,000 + $17,900 
                                           = ($32,100)