1 a i) EMPLOYEE[SSN]
   ii) CUSTOMER[CustName]
  iii) (CUSTOMER WHERE City='Chicago')[CustName]
   iv) CUSTOMER[CustID] - ORDER[CustID]
    v) ((CUSTOMER WHERE CustName='Citibank') 
         JOIN (CUSTOMER.CustID=ORDER.CustID)
        (ORDER WHERE Amount>50000))[OrderDesc, Amount]
   vi) (CUSTOMER JOIN (CUSTOMER.CustID=ORDER.CustID)
        (ORDER WHERE Amount>75000))[CustName, Address]

1 b i) UNION
   
       SSN
       ----------
       145-09-966
       145-09-967
       145-09-968

   ii) DIFFERENCE
   
       SSN
       ----------
       145-09-967

  iii) PRODUCT
   
       SSN         OrderID
       -------------------
       145-09-966    100
       145-09-966    102
       145-09-966    103
       145-09-967    100
       145-09-967    102
       145-09-967    103
     
2. See lecture notes

3. See lecture notes