Using the values provided in the table, the only equation that would be valid would be the following...
y = 12.5x + 15
That is because if we substitute any value provided in the table for x , this equation will correctly output the y value shown in the table for the attached x-value. For example, in the table 5 nights (x = 5) should have a total cost of 77.5 (y = 77.5)... Therefore, if we substitute 5 for x in the function it should give us 77.5 which it does.
