A new store opens in New York. You received a coupon for $5.00 off a pair of jeans j(x) = x-5. When you get to the store you learn that they are giving a 25% discount d(x)=.75x

a) Write a composite function for the cost of the jeans if the 25% discount is applied after the $5.00 coupon

b) Write a composite function for the cost of the jeans if the 25% discount is applied before the $5.00 coupon

c) Using both composite functions determine what you will pay for a pair of jeans with a regular price of $30.00? Which is a better deal?

User Icon for Steve Steve answered
10 years ago

(a) d(j(x)) = .75(j(x)) = .75(x-5)

(b) j(d(x)) = d(x)-5 = .75x - 5
(c) go for it

User Icon for Explain Bot Explain Bot answered
11 months ago

To answer these questions, we will need to create composite functions and evaluate them using the given conditions.

a) To write a composite function for the cost of the jeans when the 25% discount is applied after the $5.00 coupon, we need to first calculate the cost of the jeans after the coupon is applied, and then apply the 25% discount on the resulting price.

Let's break it down step by step:

1. Apply the $5.00 coupon to the original price: j(x) = x - 5
(This represents the cost of the jeans after the coupon is applied)

2. Apply the 25% discount to the resulting price from step 1:
d(j(x)) = 0.75 * j(x)
= 0.75 * (x - 5)
= 0.75x - 3.75

Therefore, the composite function for the cost of the jeans with the 25% discount applied after the $5.00 coupon is d(j(x)) = 0.75x - 3.75.

b) To write a composite function for the cost of the jeans when the 25% discount is applied before the $5.00 coupon, we need to first apply the 25% discount to the original price, and then subtract the $5.00 coupon from the resulting price.

Again, let's break it down step by step:

1. Apply the 25% discount to the original price: d(x) = 0.75x
(This represents the cost of the jeans after the discount is applied)

2. Apply the $5.00 coupon to the resulting price from step 1:
j(d(x)) = d(x) - 5
= 0.75x - 5

Therefore, the composite function for the cost of the jeans with the 25% discount applied before the $5.00 coupon is j(d(x)) = 0.75x - 5.

c) Now, we can use both composite functions to determine the cost of a pair of jeans with a regular price of $30.00 and compare which option is a better deal (lower price).

Using the first composite function (25% discount after $5.00 coupon):
d(j(30)) = 0.75 * (30 - 5)
= 0.75 * 25
= $18.75

Using the second composite function (25% discount before $5.00 coupon):
j(d(30)) = 0.75 * 30 - 5
= 22.5 - 5
= $17.50

Therefore, with a regular price of $30.00, the cost of the jeans would be $18.75 with the 25% discount applied after the $5.00 coupon, and $17.50 with the 25% discount applied before the $5.00 coupon. The second option, applying the discount before the coupon, is a better deal as it results in a lower price.