How many are in the morning class?

Question

There were 84 students signed up for algebra. There were 9 more in the afternoon as the morning class and 6 less in the evening as the morning. How many were in the morning class?

Answer 1

morning class = x

afternoon class= x + 9

evening class= x-6

x + x + 9 + x - 6 = 84

3x + 3 = 84

3x = 81

x = 27

afternoon class = 27 + 9 = 36

evening class = 27 - 6 = 21