The cost to produce one compact disc is ​$1.75 plus a​ one-time fixed cost of ​$3000 The revenue received from selling one compact disc is ​$13

​(a) Write a formula that gives the cost C of producing x compact discs. Be sure to include the fixed cost.

C=

The formula that gives the cost C of producing x compact discs is:

C = 1.75x + 3000

​(b) Write a formula that gives the revenue R from selling x compact discs

The formula that gives the revenue R from selling x compact discs is:

R = 13x

(c) Profit equals revenue minus cost. Write a formula that calculates the profit P from selling x compact discs.

The formula that calculates the profit P from selling x compact discs is:

P = R - C

Substituting the formulas for revenue and cost:

P = 13x - (1.75x + 3000)

Simplifying:

P = 11.25x - 3000

​(d) How many compact discs need to be sold to yield a positive​ profit?

To find how many compact discs need to be sold to yield a positive profit, we need to set the profit formula equal to zero and solve for x:

11.25x - 3000 = 0

Adding 3000 to both sides:

11.25x = 3000

Dividing both sides by 11.25:

x = 3000 / 11.25

x ≈ 266.67

Since we cannot sell a fraction of a compact disc, we round up to the nearest whole number. Therefore, we need to sell at least 267 compact discs to yield a positive profit.