a) There are twice as many students in the math club as in the telescope club. Suppose there are $x$ students in the telescope club and $y$ students who are members of both clubs. Find an expression for the total number of students who are in the math club or the telescope club (or both). Give your answer in simplest form.
b) There are twice as many students in the math club as in the telescope club. Suppose there are $x$ students in the telescope club and $y$ students who are members of both clubs. Find an expression for the total number of students who are in the math club or the telescope club but not both. Give your answer in simplest form.
