Expressions and Equations Algebra I Expressions and Equations

General little statements that Expressions are: General little statements that DO NOT have an equals sign! 2x – 4 2m³ + 5m Seven less than half a number squared Twice the difference of a number and five

Any statement that DOES have an equals sign (or equivalent): Equations are: Any statement that DOES have an equals sign (or equivalent): 4n + 7 = 11 ½ b – 2 = 3 Twice a number increased by four is ten The difference of a number and two is five

What you will be doing today: Writing verbal expressions and equations from algebraic forms Writing algebraic expressions and equations from verbal forms

What does THAT mean? It means you will take an expression like 3x – 5, and write it as: “the difference of three times a number and five” or maybe “ five less than three times a number”

Or maybe…… If you are given the verbal sentence, you will write it as an algebra equation or expression: “half of a number increased by three is twelve” would be written as : ½ x + 3 = 12

What will you need to know to be able to do this? Words for addition, such as “more than” or “increased by.” Or the word “Sum” Words for subtraction, such as “less than” or “decreased by.” Or the word “Difference.” Words for multiplying or dividing, such as “product of” or “quotient.” “Per” is also used for mutliplying. Words for powers of numbers, like “squared” or “cubed” Words for where the equals sign goes, like ‘is” or “is equal to” or “is the same as”

Do not use the words “plus” or “minus” Warning!! Do not use the words “plus” or “minus” or “equals” if at all possible !!

The product of 4 and number increased by 3 Your turn: How would you write 4n + 3 as a verbal expression? The product of 4 and number increased by 3

Can you write the following in algebraic form? Now try this one: Can you write the following in algebraic form? “3 less than a number cubed is the same as five”

Which ones are correct for 2m – 7: Twice a number less than seven Seven decreased by twice a number Seven less than twice a number Twice a number decreased by seven

3m² + 2 = 14 would be written: Two more than 3 times a number squared is fourteen Three m’s squared plus two equals fourteen Three times a number squared increased by two is the same as fourteen

Your Homework: Worksheet 3-6 Or Pg 124 13-37 odd, and 41-52 all

Created by: Mr. Judd