Simple Algebraic Expressions and Equations

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3. Example 1-4b Objective Write verbal phrases and sentences as simple algebraic expressions and equations

4. Example 1-4b Review Vocabulary Expression A combination of variables, numbers, and at least one operation (no equal sign) x - 7 Equation Two expressions that have the same value on each sign of the equal sign x - 7 = 13 Where x = 20

5. Example 1-4b Subtraction Expressions Less Numbers in order read 8 less a number 8 - x A number less 8 x - 8 Less than Number that is “less than” will come after the subtraction sign 8 less than a number x - 8 A number less than 8 8 - x

6. Example 1-4b Multiplication Expressions Twice Multiply by 2 Twice a number 2x Division Expressions Half Divide by 2 Half a number x 2

7. Lesson 1 Contents Example 1Write a Phrase as an Expression Example 2Write a Sentence as an Equation Example 3Write Sentences as Equations Example 4Write Sentences as Equations

8. Example 1-1a price of a Write the phrase twenty dollars less the price of a movie ticket as an algebraic expression. movie ticket twenty dollars less the price of a movie ticket Write the phrase Define the variable m = price of movie ticket Determine process word 20 - m “less” means subtract in order of numbers Answer: 1/4

9. Example 1-1b Write the phrase five more inches of snow than last year’s snowfall as an algebraic expression. Answer: 1/4

10. Example 1-2a a number less 4 is 12 Write the sentence a number less 4 is 12 as an algebraic equation. a number less 4 is 12 Write the phrase Define the variable n = a number Determine process word n - 4 = 12 “less” means subtract in order of numbers Determine what the expressions equals Answer: n - 4 = 12 2/4

11. Example 1-2b Write the sentence eight less than a number is 12 as an algebraic equation. Answer: 2/4

12. Example 1-3a twice a number is 18 Write the sentence twice a number is 18 as an algebraic equation. twice a number is 18 Write the phrase Define the variable n = a number Determine process word = 18 2n “twice” refers to multiply by 2 Determine what the expressions equals Answer: 2n = 18 3/4

13. Example 1-3b Write the sentence four times a number equals 96 as an algebraic equation. Answer: 3/4

14. Example 1-4a FOOD An average American adult drinks more soft drinks than any other beverage each year. Three times the number of gallons of soft drinks plus 27 is equal to the total 183 gallons of beverages consumed. Write an equation that models this situation. the number of gallons of soft drinks Define the variable d = the number of gallons of soft drinks Determine process word “three times” refers to multiply the number by 3 3d + 27 Determine the next process word “plus” refers to addition 4/4

15. Example 1-4a FOOD An average American adult drinks more soft drinks than any other beverage each year. Three times the number of gallons of soft drinks plus 27 is equal to the total 183 gallons of beverages consumed. Write an equation that models this situation. the number of gallons of soft drinks Determine what the expressions equals d = the number of gallons of soft drinks 3d + 27 = 183 Answer: 3d + 27 = 183 4/4

16. Example 1-4b * EXERCISE It is estimated that American adults spend an average of 8 hours per month exercising. This is 26 hours less than twice the number of hours spent watching television each month. Write an equation that models this situation. Answer: 4/4

17. End of Lesson 1 Assignment