Kim’s birthday party cost $10 plus $2 per guest. What expression represents the cost for n number of guests?

The expression that represents the cost for n number of guests is $10 +$2n. Here's how we get it:

1. The fixed cost of the party is $10. This is a one-time cost that doesn't change regardless of the number of guests.

2. The variable cost is $2 per guest. This cost changes depending on the number of guests. If we represent the number of guests as 'n', then the cost for the guests is$2n.

3. To find the total cost of the party, we add the fixed cost and the variable cost together. So, the total cost is $10 (fixed cost) +$2n (variable cost).

So, the expression representing the cost for n number of guests is $10 +$2n.