1 / 15

WRITING AND EVALUATING ALGEBRAIC EXPRESSIONS

WRITING AND EVALUATING ALGEBRAIC EXPRESSIONS. Algebra Review Unit. Algebra magic. 1. Think of a number – shh! Don’t tell me! 2. Double it in your head. 3. Add 6. 4. Divide by 2. 5. Subtract the original number from your new number – shh! Let me guess the number you ended up with….

brigid
Télécharger la présentation

WRITING AND EVALUATING ALGEBRAIC EXPRESSIONS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. WRITING AND EVALUATING ALGEBRAIC EXPRESSIONS Algebra Review Unit

  2. Algebra magic 1. Think of a number – shh! Don’t tell me! 2. Double it in your head. 3. Add 6. 4. Divide by 2. 5. Subtract the original number from your new number – shh! Let me guess the number you ended up with…..

  3. Did you get… 3 I bet you’re wondering how I knew that! Let’s use some algebra to find out!

  4. Let’s translate our words into algebra WORDS ALGEBRA 1. Think of a number. 2. Double it in your head. 3. Add 6. 4. Divide by 2. 5. Subtract the original number from your new number. Let’s call our number n n + n = 2n 2n + 6 2n + 6 simplifies to: n + 3 2 n + 3 – n simplifies to: 3

  5. Let’s review some important vocabulary words • A variableis a symbol that represents one or more numbers. • Examples of variables are: n number of students t time in minutes x may represent any number for any reason • A termis a number, variable or the product of a number and variable(s). • Examples of terms are: 3x z 2ab 5y3

  6. A coefficientis the numeric factor of your term. • An algebraic expressionis a mathematical phrase with at least one variable. • Examples of algebraic expressions are: 3m 4t + 12 2x - 3 n + 8

  7. algebraic expressions can represent word phrases

  8. Key words and phrases used to describe mathematical operations

  9. Write an algebraic expression for each word phrase • swimming m meters per minute for 3 minutes • 12 heartbeats more than xheartbeats • a price p decreased by 16 • the quotient of q and 6 3m x + 12 p - 16 q 6

  10. The cost of a package of markers is d dollars. Write an algebraic expression for the total cost in dollars of 7 packages of markers. WORDS: NUMBER OF PACKAGESTIMESCOST PER PACKAGE Let d = cost per package An algebraic expression for the total cost in dollars is 7d

  11. Nine students will purchase b books each. Write an algebraic expression for the total number of books the students will buy. WORDS: NUMBER OF STUDENTSTIMES# OF BOOKS PURCHASED EACH Let b = # of books purchased each An algebraic expression for the total number of books is 9b

  12. What is the cost of one pen if a package of 12 pens costs d dollars? WORDS: COST PER PACKAGEDIVIDED BY# OF PENS IN PACKAGE Let d = cost per package An algebraic expression for the total cost in dollars is d 12

  13. we can also write word phrases from algebraic expressions • Write three different word phrases for x + 2 • a number plus 2 • a number increased by 2 • two more than a number • Write three different word phrases for c - 50 • a number minus 50 • a number decreased by 50 • 50 less than a number

  14. steps for evaluating algebraic expressions • Replace the variables with the values that have been given. • Follow the rules for the order of operations. Example: Evaluate 50 – 3x when x = 7 a. write the expression 50 – 3x b. replace the variable with its given value 50 – 3(7) c. multiply 50 – 21 d. subtract29

  15. Evaluate these algebraic expressions • 8x + 2 let x = 3 • 9nlet n = 4 6 • 10ab – 15 let a = 2 let b = 5 8(3) + 2 24 + 2 26 9(4) 6 36 = 6 6 10(2)(5) – 15 20(5) – 15 100 – 15 85

More Related