Question 896244:  The carnival charges $7 for admission and $2 for every book of ride tickets.  Write the equation that would describe how many books of tickets you can buy for $25.  Use "b" for the number of books and DO NOT use spaces. 
 Answer by jim_thompson5910(35256)      (Show Source): 
You can  put this solution on YOUR website! The $7 is the fixed cost. It does not change based on how many tickets you buy. 
 
 
The $2 is known as the variable cost. It changes based on how many ticket books you buy.
 
 
Let b = number of ticket books bought
 
 
If it costs $7 to get in the door, and $2 per book, then it costs 7 + 2b or 2b + 7 dollars total. This is the sum of the fixed cost and variable cost.
 
 
This total cost is equal to $25 because this is how much you have in your pocket.
 
 
 
So the equation is 2b + 7 = 25
 
 
-------------------------------------------------------
 
 
If you want to solve for b, then...
 
 
 
2b + 7 = 25
 
 
2b + 7-7 = 25-7
 
 
2b + 0 = 18
 
 
2b = 18
 
 
2b/2 = 18/2
 
 
b = 9
 
 
 
Therefore, you can buy 9 books with $25. If you only want the equation, then ignore this portion. However, it is useful to know how solve equations. 
  | 
 
  
 
 |   
 
 |