According to the four tables in the following, use appropriate relational algebra to derive the answers....

 

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According to the four tables in the following, use appropriate relational algebra to derive the answers. (1) Write step-by-step relational algebra retrieve the ECode of employees whose last name is "Smith". (2) Write step-by-step relational algebra to retrieve last name of employees whose job description is "Clerical". (3) Write step-by-step relational algebra to retrieve last name of employees who has 'Stock Option' benefit. (4) Write step-by-step relational algebra to retrieve name of employee whose job description is *Technical and who has 'Stock Option' benefit. (5) Write step-by-step relational algebra to retrieve ECode of employees who do not have any benefit plans. EMPLOYEES ECode 14 15 16 17 20 JOBS JCode 1 2 3 EName Rudell McDade Ruellardo Smith Smith JDesc Clerical Technical Managerial JCode 2 1 1 3 2 BENEFITS ECode 1 2 3 4 15 15 16 17 17 17 20 PLANS PCode PCode 2 3 1 1 3 4 3 PDesc Term Life Stock Option Long-Term Disability Dental According to the four tables in the following, use appropriate relational algebra to derive the answers. (1) Write step-by-step relational algebra retrieve the ECode of employees whose last name is "Smith". (2) Write step-by-step relational algebra to retrieve last name of employees whose job description is "Clerical". (3) Write step-by-step relational algebra to retrieve last name of employees who has 'Stock Option' benefit. (4) Write step-by-step relational algebra to retrieve name of employee whose job description is *Technical and who has 'Stock Option' benefit. (5) Write step-by-step relational algebra to retrieve ECode of employees who do not have any benefit plans. EMPLOYEES ECode 14 15 16 17 20 JOBS JCode 1 2 3 EName Rudell McDade Ruellardo Smith Smith JDesc Clerical Technical Managerial JCode 2 1 1 3 2 BENEFITS ECode 1 2 3 4 15 15 16 17 17 17 20 PLANS PCode PCode 2 3 1 1 3 4 3 PDesc Term Life Stock Option Long-Term Disability Dental