Just Some Math I Know...

A 30% discount for a latte at Starbucks gives a total price of $14.00. What was the original price? How much was discounted?

Original Price:
.7x = 14
x = 20
The original price was $20.00.

Amount Discounted:
20 - 14 = y
y = 6
The amount discounted was $6.00.


The length of a rectangle is 7 less than 3 times the width. Its perimeter is 42. Find both values.

Width (y):
8y - 14 = 42
8y = 56
y = 7

Length (x):
x = 3(7) - 7
x = 21 - 7
x = 14


Juan and Alex go to a taco stand. Juan buys three tacos and two quesadillas. He pays $42. Alex buys two tacos and one quesadilla. He pays $30. How much is one taco? How much is one quesadilla?

   3x + 2y = 42
- 4x + 2y = 30
---------------
-x = -12
x = 12

2(12) + y = 30
24 + y = 30
y = 6

One taco costs $12.00. One quesadilla costs $6.00.


I'm such a nerd... =_=v