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 but not both. Give your answer in simplest form.
The number of students ONLY in math class is a-b.
The number of students ONLY in science class is c-(a-b) = c-a+b.
The number of students ONLY in science class is just c-a.
So, we just have a-b + c - a = c - b.
Thanks! :)