Heather, chang, and justin served a total of 93 orders monday at the school cafeteria. chang served 2 times as many orders as justin. heather served 5 more orders than justin. how many orders did they each serve?

Let the # of orders sold by these 3 people be represented by H, C and J.
Then H+C+J=93.
C=2J
H=J+5
Find H, C and J.

Let's eliminate C.  Substitute 2J for C in      H+C+J=93:  H+2J+J = 93
Now let's eliminate H:  Subst. J+5 for H in this last equation:

J+5   +   2J   +   J  =  93   =>       4J + 5 = 93   => 4J = 88.

Thus, J = 88/4 = 22.

J handles 22 orders.
H handles 22+5 (or 27) orders.
C handles the rest:  2(22) (or 44) orders.

Check:  do the numbers 22, 27 and 44 add up to 93, as they must?  Yes.