Which system could be used to solve the following: a manager is comparing two companies. company a charges $50 plus $7 per item. company b charges $30 plus $9 per item. for what number of items will the cost be the same at both companies? (a) y=7+50x y=30+9x (b) y=50+7x y=30x+9 (c) y=50+7x y=30+9x (d) y=50x+7 y=30x+9

(C)

10

Step-by-step explanation:

Let y = cost of items

Let x = number of items

Total cost  = fixed charge + (cost per item x number of items)

Given:

company A fixed charge = $50 , cost per item = $7

company B fixed charge = $30 , cost per item = $9

For company A,

Total Cost = $50 + ($7 x number of items),

          or

     y = 50 + 7x

Similarly for company B,

Total Cost = $30 + ($9 x number of items),

          or

     y = 30 + 9x

Hence (C) is the correct answer.

For the cost to be the same, Total cost for A = total cost for B

i.e 50 + 7x = 30 + 9x

x = 10 items  (Answer)