Tickets to play cost 11$ each. There is also a service charge of 4$ per order. Write an equation for the relationship that gives the total cost y in dollars for an order of x tickets.

We are going to use the common formula y=mx+b
So, we have already been given what y and x equal. So we must figure out what m and b is... since x is the number of tickets and $11 is the cost per ticket, we are going to make x=11 and so that leave b for our other value which is 4, so if we plug these values in our answer will be:
y= 11x+4