Math
posted by Tim .
A manufacturer produces certain devices. The fixed cost of production is $2000. The first unit produced cost $2 and the cost per unit increases by 20 cents or each additional unit produced. What is the total cost C of producing x units?

The premise is faulty. From your data, the first would cost $2 to produce, the second $2.20, the third $2.40, which sounds illogical. Articles can be produced more cheaply on a mass basis.
Assuming you mean that after first one, the remaining units cost $.20 each:
C = $200 + .2(x  1)