mark ordere wome balloons for a party that she is having.The balloons cost $4.50 each and there is a service fee of $12.The total cost is $79.50. write an equation represents this situation, then solve doe how many balloons were purchased for the party.
A general equation to use for this situation is y = mx + b.
For this question, we can assume that y is total cost, m is cost per balloon, x is the amount of balloons, and b as the service fee; so we can set the equation up:
y = (4.50)x + 12
And we can further plug in the total cost to find the number of balloons purchased for the party:
79.50 = (4.50)x + 12
Now we can solve for x (number of balloons):
67.50 = (4.50)x
x = 15
The total number of balloons purchased for the party is 15.