Answer:
Part A: C(x) = 0.068x+0.8
Part B: 1.28
Part C: 9.76
Explanation:
Part A:
The cost C equals
cost = revenue - profit

which is



Part B:
The cost of producing 7 units is found by putting in x = 7 into the above equation. This gives


Hence, the cost of producing 7 items is 1,28 million dollars.
Part C:
To break even, the cost must equal the revenue

or

subtracting 0.068 from both sides gives

dividing both sides by 0.082 gives

which is the break-even point