Question

The graph shows the total cost c of buying one large bucket of popcorn and d large drinks. Write an equation from the graph that could be used to find the total cost c if you buy one large bucket of popcorn and d large drinks.

Answer 1

`y = 4d + 8\\`

Explanation:

Since d is the number of large drinks, and there is always a constant of 1 large popcorn, we go to (0, 8). This concludes that since we start off with the cost of 8 dollars with no large drink but a large popcorn, the popcorn will stay a constant cost of $8. (the equation for this scenario is as shown):

y = md + 8

y (total cost)

m (coefficient - in this sense the cost of the drinks.)

d (amount of drinks)

8 (the constant of 8 represents the cost of one large popcorn consistently)

Now, lets find the cost of the dink.

Go to (1, 12).

$12 dollars is the total cost, with one drink and one large popcorn bought.

We have already discussed that we will have a constant of 8 because no matter the amount of drinks we will get, we would have bought 1 large popcorn at $8.

Therefore, we must subtract 8 dollars from 12.

12 - 8 = 4

From the total cost of everything we bought (2 things) and subtracting it with the cost one of the things we bought, we get the cost of the other thing.

each drink will cost $4.

Therefore, with all the variables and their listed meanings, this will be our given equation:

y = 4d + 8