Question

At a school dance, tickets are sold at the door and each ticket is the same price. the amount of money the school makes from the dance is equal to the total amount of money collected from ticket sales minus the total cost of the dj and decorations. for this dance, the total cost is fixed and is not dependent on the number of tickets sold. if 75 tickets are sold, the school loses $150. if 100 tickets are sold, the school makes $100. what is the total cost of the dj and decorations?

Answer 1

$900

Explanation:

x = the cost of the tickets

y = the cost of dj & decorations

In the first situation, the profit of -$150 = 75x - y

In the second situation, the profit of $100 = 100x - y

Using the first situation, we isolate y as follows:

-150 = 75x - y

Add y to each side: y-150 = 75x

Add 150 to each side to isolate y

y = 75x + 150

Use this formula in the second situation in place of the y

Original formula: 100 = 100x - y

With substitution: 100 = 100x - (75x + 150)

Simplify to: 100 = 25x - 150

Add 150 to both sides: 250 = 25x

Divide both sides by 25: 10 = x

Input the 10 in for x in either formula above

-150 = 75(10) - y

-150 = 750 - y

Add y to both sides

y - 150 = 750

Add 150 to both sides

y = 900