+817 North High School has a math club and a science club. There are $a$ students in the math club and $b$ students who are members of both clubs. The total number of students is $c$. Find an expression for the total number of students who are in the math club or the science club (or both). Give your answer in simplest form.
+6 The total students in either club (or both) equals the sum of math and science club members minus those in both clubs. Total = Math + Science - Both.
