70 - 5x = number of people waiting in line to buy tickets x minutes after a ticket booth opened is given by 70 - 5x. What does the value of 70 represent

The 70 represents the number of people waiting to by tickets at the exactly moment when the ticket booth is opened.

Step-by-step explanation:

The 70 represents the number of people waiting to by tickets at the exactly moment when the ticket booth is opened.

You can see this by setting the x value to 0, it is, in the precise moment when the booth opened (as x cant be negative, because there is no negative time, you could also think of 70 as the number of people waiting before the booth opens).