For this case, the first thing we must do is define variables.
We have then:
x: number of minutes
y: total cost
We write the algebraic expression that models the problem.
We have then:

Simplifying we have:

Then, by the time the cost is equal to $ 300 we have:

From here, we clear the value of x.
Answer:
an algebraic expression for the problem is:

So the first one is -0.5 and second is -0.5 the third one is -0.5 and the fourth is -0.25 so I would say that is D
1 in 13 or 1/13 because those are the only numbers it gives you and since he only sold one vanilla cone in the last thirteen cones you can only assume that he sells one vanilla every 13
Answer:
3x+4y-12=0
y intercept = -constant term/coefficient. of y
= 12/4
=3