The question is asking to find an equation of how many customers the waiter served.
Given: 12 customers at lunch; 5 per hour for dinner
Find: number of customers served at lunch AND dinner
We use variables for this, x and y. A general equation is usually y=ax+b, where y is the solution, x is the variable, and a and b are numbers.
Knowing this information, since it is already given that 12 customers were served, the equation turns into y=ax+12
Additionally, since we don't know how many hours she worked, we can use that as a variable. y=5x+12
x=how many hours the waiter worked at dinner
y=overall hours the waiter worked at both lunch and dinner
slope=5, means customers are going up 5 every hour
y-intercept=12, the given/starting point on the y-axis
