Question

Please help quick! The average cost of printing a book in a publishing company is c(x)= (5.5x+k)/x , where x is the number of books printed that day and k is a constant. Find k, if on the day when 200 were printed the average cost was $9 per book.

Answer 1

700

Explanation:

c(x)= (5.5x+k)/x

x = 200, c(x) = 9

9 = [5.5(200) + k]/200

1800 = 1100 + k

k = 700

Answer 2

k = 700

Explanation:

c(x)= (5.5x+k)/x

We know c(x) is 9 and x is 200

Substitute these values into the equation

9 = (5.5*200+k)/200

Multiply each side by 200

9*200 = (5.5*200+k)/200 *200

1800 = (5.5*200+k)

1800 =1100 + k

Subtract 1100 from each side

1800-100 = 1100+k-1100

700 =k