Transcript buy x box

Algebraic
Expressions
What is a Variable?
• In algebra, we use LETTERS or SYMBOLS
to represent a number
• Examples:
x
y
n
What is an algebraic expression?
• When we combine one or more variables;
 It can include NUMBERS and OPERATION
SIGNS
• Examples:
x+y
3–x
4x
6 + xy
Expressions that involve addition
• The sum of 2 and x
• 8 increased by 2
• 7 more than v
• 6 greater than x
• Exceeds L by 20
Expressions that involve subtraction
• The difference of 2 and y
• c decreased by 2
• 7 less than v
• 6 reduced by x
• 20 less L
Expressions that involve
multiplication
• The product of 2 and 5
• 10 times x
• Twice y
• Triple z
• ½ of a number t
Expressions that involve division
• The quotient of 20 and 5
• T divided by 4
• x split into 12 parts
Math in our everyday lives
• Johnny babysits his neighbour’s kids after
school and receives $5.50 each hour.
• Johnny really, REALLY wants to buy an XBOX
360 which is priced at $569 (with tax).
• If Johnny works 82 hours, will he have enough
money to purchase the XBOX 360?
Math in our everyday lives
IN:
1 hour, Johnny makes $5.50
2 hours: Johnny makes $11.00
3 hours: Johnny makes $16.50 …
The algebraic expression 5.50x gives us how much
money Johnny earns in x hours.
How much money does he earn in 82 hours?
$5.50 x 82 = $451 … not enough 
homework
• “Do You Remember?” section of Chapter 4
– Page 123 #1-7