Notebooks cost $7, and dividers cost $2 per pkg. which of the following could be used to determine c, the total cost of one notebook and n packages of dividers c = (7+2)n c = 7+2n c = 7n+2 c + 7+2+n

The correct option is C = 7 + 2n.
From the question given above, we are told that, a notebook costs $7 and divider cost $2 per kg.
So if you buy one notebook, it will cost $7 and
if you buy n packages of dividers, it will cost $2 * n = 2n.
If you add all the costs of the items together, you will have
Cost [C] = 7 + 2n.