A class of students do 1 of 4 different after school activities. 1/2 play soccer, 7 take karate, 9 do art or piano. How many students are in the class.
(1/2)x + 7 + 9 = x
16 = x - (1/2)x
16 = (1/2)x
16/(1/2) = x
16 * (2/1) = x
32 = x
16 = x - (1/2)x
16 = (1/2)x
16/(1/2) = x
16 * (2/1) = x
32 = x