Melissa, Juan, and Rafael served a total of 74 orders Monday at the school cafeteria. Rafael served 2 times as many orders as Juan. Melissa served 6 more orders than Juan. How many orders did they each serve?

Let's named variables as M, J and R

The equation is M+J+R=74

We will represent M with J = > M=J+6 and R=2J

when we replace in the equation we get

J+6+J+2J=74 = > 4J=74-6 = > 4J=68 = > J=68/4 = 17

J=17 = > M=6+17 = > M=23 and R=2 * 17 = > R=34

Final answer is

Juan served 17 orders

Melissa served 23 orders and

Rafael served 34 orders

Good luck!