160k views
0 votes
Reasoning A store sells packages of comic books with a poster. A poster and 3 comics cost $9.996ster and 11 comics cost

$17.99. Write a linear function rule that models the cost y of a package containing any number x of comic books.
Suppose another store sells a similar package, modeled by a linear function rule with initial value $6.50. Use pencil and paper. Explain
which store has the better deal.

The linear function rule is y= ?

1 Answer

1 vote

Answer:

Explanation:

Let's start by defining some variables. Let "p" be the cost of a poster and "c" be the cost of a comic book.

From the problem statement, we know that a poster and 3 comics cost $9.99. We can express this as:

p + 3c = 9.99

We also know that 11 comics cost $17.99. We can express this as:

11c = 17.99

Solving for "c", we get:

c = 1.63

Now we can use the first equation to solve for "p":

p + 3c = 9.99

p + 3(1.63) = 9.99

p = 4.10

So a poster costs $4.10.

The total cost of a package with x comic books and one poster can be expressed as:

y = px + 3cx

Substituting the values we found for "p" and "c", we get:

y = 4.10x + 3(1.63)x

Simplifying this equation, we get:

y = 10.99x

So the linear function rule that models the cost y of a package containing any number x of comic books is y = 10.99x.

Now let's consider the second store, which sells a similar package modeled by the linear function rule with an initial value of $6.50. This means that the cost of a package with no comic books is $6.50. We can express this as:

y = 6.50 + cx

where "c" is the cost of a single comic book.

To compare the two stores, we need to find the cost of a package with a certain number of comic books at each store. Let's say we want to compare the cost of a package with 5 comic books.

For the first store, we can use the linear function rule we derived earlier:

y = 10.99x

y = 10.99(5) = $54.95

For the second store, we can use the linear function rule:

y = 6.50 + cx

y = 6.50 + 5c

We know that the total cost of a package with 11 comic books is $17.99, so we can use this information to find "c":

11c = 17.99

c = 1.63

Now we can substitute this value of "c" into the equation for the cost of a package with 5 comic books:

y = 6.50 + 5c

y = 6.50 + 5(1.63)

y = $14.95

Therefore, the package with 5 comic books is cheaper at the second store, which sells a similar package modeled by the linear function rule with an initial value of $6.50.

User Funerr
by
7.0k points