Relational Algebra be the following scheme. **CAREERS(idcareer, namecareer)** **COURSES(idcourse, coursename)** **STUDENTS(account, name, idcareer)** **GRADES(account, idcourse, grade, idcourse)** Perform the following queries using relational algebra: 1. Show how many students there are in total. 2. Show the name of the student and the career to which he belongs. 3. Show the names of the students with grades greater than 10. 4. Show only the grades of the student 'Pedro'. 5. Show student name, course name and grade for all students. 6. Show the name of the student with the highest grade. Hint: Once you have generated your expression in relational algebra, try its ne *MySQL* equivalent to make sure it works.