Answer:
Total Students = 3a - 2b
Step-by-step explanation:
Given
Students in drama club = a
There are twice as many students in cooking club as in drama club;
So, Students in cooking club = 2a
Members of both clubs = b
Required
Expression for total students in cooking or drama club but not both;
To do this, number of students in individual clubs need to be calculated;
Let Students in drama club only be represented by D and Students in cooking club only be represented by C
So,
D = Students in drama club - Members of both clubs
D = a - b
Similarly,
C = Students in cooking club - Members of both clubs
C = 2a - b
So, total students in cooking or drama club but not both D + C
Total students = a - b + 2a - b
Collect like terms
Total Students = a + 2a - b - b
Total Students = 3a - 2b