The linear function of the cost needs to be determined.
Using the given cost function,
C(x) = mx + b, where m = cost of each toy; x = number of toys produced; b = innitial cost of manufacturing:
C(x) = 5x + 2600
To answer the second part of the question: cost of producing 2 toys, we have:
C(x) = 5(2) + 26000
C(x) = 10 + 2600
C(x) = $2610