SECTION 2-3
 Write Variable Expressions
ESSENTIAL
QUESTIONS
How do you write variable expressions to represent word
phrases?

How do you write word phrases to represent variable
expressions?



Where you’ll see this:

  Part-time jobs, space science, photography, population
SOME VERY
IMPORTANT IDEAS
SOME VERY
IMPORTANT IDEAS

Most commonly used variables: x and y
SOME VERY
IMPORTANT IDEAS

Most commonly used variables: x and y

Only place holders
SOME VERY
IMPORTANT IDEAS

Most commonly used variables: x and y

Only place holders

Represents something we don’t know
SOME VERY
IMPORTANT IDEAS

Most commonly used variables: x and y

Only place holders

Represents something we don’t know

Remember: Variables represent a number
SOME VERY
IMPORTANT IDEAS

Most commonly used variables: x and y

Only place holders

Represents something we don’t know

Remember: Variables represent a number

Translate!
TRANSLATIONS
 Rewrite the word phrase as a variable expression




            Four more than a number
TRANSLATIONS
 Rewrite the word phrase as a variable expression




            Four more than a number




                      x+4
TRANSLATIONS
 Rewrite the word phrase as a variable expression




        The difference of a number and 15
TRANSLATIONS
 Rewrite the word phrase as a variable expression




        The difference of a number and 15




                      q - 15
TRANSLATIONS
 Rewrite the word phrase as a variable expression




              Three times a number
TRANSLATIONS
 Rewrite the word phrase as a variable expression




              Three times a number




                       3r
TRANSLATIONS
 Rewrite the word phrase as a variable expression




         The quotient of a number and 5
TRANSLATIONS
 Rewrite the word phrase as a variable expression




         The quotient of a number and 5




                         t
                         5
TRANSLATIONS
 Rewrite the word phrase as a variable expression




            Eight less than a number
TRANSLATIONS
 Rewrite the word phrase as a variable expression




            Eight less than a number




                      y-8
TRANSLATIONS
 Rewrite the word phrase as a variable expression




          The sum of a number and -10
TRANSLATIONS
 Rewrite the word phrase as a variable expression




          The sum of a number and -10




                 b + -10
TRANSLATIONS
 Rewrite the word phrase as a variable expression




          The sum of a number and -10




                 b + -10 = b - 10
TRANSLATIONS
 Rewrite the word phrase as a variable expression




         The product of a number and 15
TRANSLATIONS
 Rewrite the word phrase as a variable expression




         The product of a number and 15




                       15u
TRANSLATIONS
 Rewrite the word phrase as a variable expression




             Six divided by a number
TRANSLATIONS
 Rewrite the word phrase as a variable expression




             Six divided by a number




                       6
                       w
TRANSLATIONS
 Rewrite the word phrase as a variable expression




          A number increased by twelve
TRANSLATIONS
 Rewrite the word phrase as a variable expression




          A number increased by twelve




                      h + 12
TRANSLATIONS
 Rewrite the word phrase as a variable expression




          A number multiplied by four
TRANSLATIONS
 Rewrite the word phrase as a variable expression




          A number multiplied by four




                        4j
TRANSLATIONS
 Rewrite the word phrase as a variable expression




      Negative five decreased by a number
TRANSLATIONS
 Rewrite the word phrase as a variable expression




      Negative five decreased by a number




                      -5 - f
TRANSLATIONS
  Rewrite the word phrase as a variable expression




 Twelve less than the quotient of a number and seven
TRANSLATIONS
  Rewrite the word phrase as a variable expression




 Twelve less than the quotient of a number and seven




                       m
                         − 12
                       7
EXAMPLE 1
    Write each phrase as a variable expression.

      a. Twice the sum of a number and three




  b. Six less than the product of a number and ten
EXAMPLE 1
    Write each phrase as a variable expression.

      a. Twice the sum of a number and three

                     2(v + 3)


  b. Six less than the product of a number and ten
EXAMPLE 1
    Write each phrase as a variable expression.

      a. Twice the sum of a number and three

                     2(v + 3)


  b. Six less than the product of a number and ten

                      10p -6
EXAMPLE 2
Translate the following variable expressions back into word phrases



                           a. 3(x + 10)




                             b. 8n - 5
EXAMPLE 2
Translate the following variable expressions back into word phrases



                           a. 3(x + 10)

             Three times the sum of a number and ten


                             b. 8n - 5
EXAMPLE 2
Translate the following variable expressions back into word phrases



                           a. 3(x + 10)

             Three times the sum of a number and ten


                             b. 8n - 5

         Five less than the product of eight and a number
WHAT’S THE BIG
DEAL?
WHAT’S THE BIG
DEAL?


Helps solving real world situations
WHAT’S THE BIG
DEAL?


Helps solving real world situations

Helps break into steps
WHAT’S THE BIG
DEAL?


Helps solving real world situations

Helps break into steps

Solve in steps, not as a whole
EXAMPLE 3
Matt Mitarnowski makes and sells candles. For his medium-sized
pillar candles, he charges $5.50 each for the unscented ones and
 $7.00 each for the scented ones. Write a variable expression to
show how much Matt earns when he sells his medium-sized pillar
candles. Then figure out how much he has made when he sells 6
               unscented and 10 scented candles.
EXAMPLE 3
Matt Mitarnowski makes and sells candles. For his medium-sized
pillar candles, he charges $5.50 each for the unscented ones and
 $7.00 each for the scented ones. Write a variable expression to
show how much Matt earns when he sells his medium-sized pillar
candles. Then figure out how much he has made when he sells 6
               unscented and 10 scented candles.

       Let u = unscented candles and s = scented candles
EXAMPLE 3
Matt Mitarnowski makes and sells candles. For his medium-sized
pillar candles, he charges $5.50 each for the unscented ones and
 $7.00 each for the scented ones. Write a variable expression to
show how much Matt earns when he sells his medium-sized pillar
candles. Then figure out how much he has made when he sells 6
                unscented and 10 scented candles.

       Let u = unscented candles and s = scented candles

5.50u + 7.00s
EXAMPLE 3
Matt Mitarnowski makes and sells candles. For his medium-sized
pillar candles, he charges $5.50 each for the unscented ones and
 $7.00 each for the scented ones. Write a variable expression to
show how much Matt earns when he sells his medium-sized pillar
candles. Then figure out how much he has made when he sells 6
                unscented and 10 scented candles.

       Let u = unscented candles and s = scented candles

5.50u + 7.00s     5.50(6)+ 7.00(10)
EXAMPLE 3
Matt Mitarnowski makes and sells candles. For his medium-sized
pillar candles, he charges $5.50 each for the unscented ones and
 $7.00 each for the scented ones. Write a variable expression to
show how much Matt earns when he sells his medium-sized pillar
candles. Then figure out how much he has made when he sells 6
                unscented and 10 scented candles.

       Let u = unscented candles and s = scented candles

5.50u + 7.00s     5.50(6)+ 7.00(10) = 33.00 + 70.00
EXAMPLE 3
Matt Mitarnowski makes and sells candles. For his medium-sized
pillar candles, he charges $5.50 each for the unscented ones and
 $7.00 each for the scented ones. Write a variable expression to
show how much Matt earns when he sells his medium-sized pillar
candles. Then figure out how much he has made when he sells 6
                unscented and 10 scented candles.

       Let u = unscented candles and s = scented candles

5.50u + 7.00s     5.50(6)+ 7.00(10) = 33.00 + 70.00 = $103.00
EXAMPLE 3
Matt Mitarnowski makes and sells candles. For his medium-sized
pillar candles, he charges $5.50 each for the unscented ones and
 $7.00 each for the scented ones. Write a variable expression to
show how much Matt earns when he sells his medium-sized pillar
candles. Then figure out how much he has made when he sells 6
               unscented and 10 scented candles.
EXAMPLE 3
Matt Mitarnowski makes and sells candles. For his medium-sized
 pillar candles, he charges $5.50 each for the unscented ones and
  $7.00 each for the scented ones. Write a variable expression to
show how much Matt earns when he sells his medium-sized pillar
 candles. Then figure out how much he has made when he sells 6
                unscented and 10 scented candles.

Matt makes $103.00 by selling 6 unscented and 10 scented candles
PROBLEM SET
PROBLEM SET


                         p. 64 #1-41 odd




“Our greatest glory is not in never failing but in rising every time
                       we fall.” - Confucius

Int Math 2 Section 2-3

  • 1.
    SECTION 2-3 WriteVariable Expressions
  • 2.
    ESSENTIAL QUESTIONS How do youwrite variable expressions to represent word phrases? How do you write word phrases to represent variable expressions? Where you’ll see this: Part-time jobs, space science, photography, population
  • 3.
  • 4.
    SOME VERY IMPORTANT IDEAS Mostcommonly used variables: x and y
  • 5.
    SOME VERY IMPORTANT IDEAS Mostcommonly used variables: x and y Only place holders
  • 6.
    SOME VERY IMPORTANT IDEAS Mostcommonly used variables: x and y Only place holders Represents something we don’t know
  • 7.
    SOME VERY IMPORTANT IDEAS Mostcommonly used variables: x and y Only place holders Represents something we don’t know Remember: Variables represent a number
  • 8.
    SOME VERY IMPORTANT IDEAS Mostcommonly used variables: x and y Only place holders Represents something we don’t know Remember: Variables represent a number Translate!
  • 9.
    TRANSLATIONS Rewrite theword phrase as a variable expression Four more than a number
  • 10.
    TRANSLATIONS Rewrite theword phrase as a variable expression Four more than a number x+4
  • 11.
    TRANSLATIONS Rewrite theword phrase as a variable expression The difference of a number and 15
  • 12.
    TRANSLATIONS Rewrite theword phrase as a variable expression The difference of a number and 15 q - 15
  • 13.
    TRANSLATIONS Rewrite theword phrase as a variable expression Three times a number
  • 14.
    TRANSLATIONS Rewrite theword phrase as a variable expression Three times a number 3r
  • 15.
    TRANSLATIONS Rewrite theword phrase as a variable expression The quotient of a number and 5
  • 16.
    TRANSLATIONS Rewrite theword phrase as a variable expression The quotient of a number and 5 t 5
  • 17.
    TRANSLATIONS Rewrite theword phrase as a variable expression Eight less than a number
  • 18.
    TRANSLATIONS Rewrite theword phrase as a variable expression Eight less than a number y-8
  • 19.
    TRANSLATIONS Rewrite theword phrase as a variable expression The sum of a number and -10
  • 20.
    TRANSLATIONS Rewrite theword phrase as a variable expression The sum of a number and -10 b + -10
  • 21.
    TRANSLATIONS Rewrite theword phrase as a variable expression The sum of a number and -10 b + -10 = b - 10
  • 22.
    TRANSLATIONS Rewrite theword phrase as a variable expression The product of a number and 15
  • 23.
    TRANSLATIONS Rewrite theword phrase as a variable expression The product of a number and 15 15u
  • 24.
    TRANSLATIONS Rewrite theword phrase as a variable expression Six divided by a number
  • 25.
    TRANSLATIONS Rewrite theword phrase as a variable expression Six divided by a number 6 w
  • 26.
    TRANSLATIONS Rewrite theword phrase as a variable expression A number increased by twelve
  • 27.
    TRANSLATIONS Rewrite theword phrase as a variable expression A number increased by twelve h + 12
  • 28.
    TRANSLATIONS Rewrite theword phrase as a variable expression A number multiplied by four
  • 29.
    TRANSLATIONS Rewrite theword phrase as a variable expression A number multiplied by four 4j
  • 30.
    TRANSLATIONS Rewrite theword phrase as a variable expression Negative five decreased by a number
  • 31.
    TRANSLATIONS Rewrite theword phrase as a variable expression Negative five decreased by a number -5 - f
  • 32.
    TRANSLATIONS Rewritethe word phrase as a variable expression Twelve less than the quotient of a number and seven
  • 33.
    TRANSLATIONS Rewritethe word phrase as a variable expression Twelve less than the quotient of a number and seven m − 12 7
  • 34.
    EXAMPLE 1 Write each phrase as a variable expression. a. Twice the sum of a number and three b. Six less than the product of a number and ten
  • 35.
    EXAMPLE 1 Write each phrase as a variable expression. a. Twice the sum of a number and three 2(v + 3) b. Six less than the product of a number and ten
  • 36.
    EXAMPLE 1 Write each phrase as a variable expression. a. Twice the sum of a number and three 2(v + 3) b. Six less than the product of a number and ten 10p -6
  • 37.
    EXAMPLE 2 Translate thefollowing variable expressions back into word phrases a. 3(x + 10) b. 8n - 5
  • 38.
    EXAMPLE 2 Translate thefollowing variable expressions back into word phrases a. 3(x + 10) Three times the sum of a number and ten b. 8n - 5
  • 39.
    EXAMPLE 2 Translate thefollowing variable expressions back into word phrases a. 3(x + 10) Three times the sum of a number and ten b. 8n - 5 Five less than the product of eight and a number
  • 40.
  • 41.
    WHAT’S THE BIG DEAL? Helpssolving real world situations
  • 42.
    WHAT’S THE BIG DEAL? Helpssolving real world situations Helps break into steps
  • 43.
    WHAT’S THE BIG DEAL? Helpssolving real world situations Helps break into steps Solve in steps, not as a whole
  • 44.
    EXAMPLE 3 Matt Mitarnowskimakes and sells candles. For his medium-sized pillar candles, he charges $5.50 each for the unscented ones and $7.00 each for the scented ones. Write a variable expression to show how much Matt earns when he sells his medium-sized pillar candles. Then figure out how much he has made when he sells 6 unscented and 10 scented candles.
  • 45.
    EXAMPLE 3 Matt Mitarnowskimakes and sells candles. For his medium-sized pillar candles, he charges $5.50 each for the unscented ones and $7.00 each for the scented ones. Write a variable expression to show how much Matt earns when he sells his medium-sized pillar candles. Then figure out how much he has made when he sells 6 unscented and 10 scented candles. Let u = unscented candles and s = scented candles
  • 46.
    EXAMPLE 3 Matt Mitarnowskimakes and sells candles. For his medium-sized pillar candles, he charges $5.50 each for the unscented ones and $7.00 each for the scented ones. Write a variable expression to show how much Matt earns when he sells his medium-sized pillar candles. Then figure out how much he has made when he sells 6 unscented and 10 scented candles. Let u = unscented candles and s = scented candles 5.50u + 7.00s
  • 47.
    EXAMPLE 3 Matt Mitarnowskimakes and sells candles. For his medium-sized pillar candles, he charges $5.50 each for the unscented ones and $7.00 each for the scented ones. Write a variable expression to show how much Matt earns when he sells his medium-sized pillar candles. Then figure out how much he has made when he sells 6 unscented and 10 scented candles. Let u = unscented candles and s = scented candles 5.50u + 7.00s 5.50(6)+ 7.00(10)
  • 48.
    EXAMPLE 3 Matt Mitarnowskimakes and sells candles. For his medium-sized pillar candles, he charges $5.50 each for the unscented ones and $7.00 each for the scented ones. Write a variable expression to show how much Matt earns when he sells his medium-sized pillar candles. Then figure out how much he has made when he sells 6 unscented and 10 scented candles. Let u = unscented candles and s = scented candles 5.50u + 7.00s 5.50(6)+ 7.00(10) = 33.00 + 70.00
  • 49.
    EXAMPLE 3 Matt Mitarnowskimakes and sells candles. For his medium-sized pillar candles, he charges $5.50 each for the unscented ones and $7.00 each for the scented ones. Write a variable expression to show how much Matt earns when he sells his medium-sized pillar candles. Then figure out how much he has made when he sells 6 unscented and 10 scented candles. Let u = unscented candles and s = scented candles 5.50u + 7.00s 5.50(6)+ 7.00(10) = 33.00 + 70.00 = $103.00
  • 50.
    EXAMPLE 3 Matt Mitarnowskimakes and sells candles. For his medium-sized pillar candles, he charges $5.50 each for the unscented ones and $7.00 each for the scented ones. Write a variable expression to show how much Matt earns when he sells his medium-sized pillar candles. Then figure out how much he has made when he sells 6 unscented and 10 scented candles.
  • 51.
    EXAMPLE 3 Matt Mitarnowskimakes and sells candles. For his medium-sized pillar candles, he charges $5.50 each for the unscented ones and $7.00 each for the scented ones. Write a variable expression to show how much Matt earns when he sells his medium-sized pillar candles. Then figure out how much he has made when he sells 6 unscented and 10 scented candles. Matt makes $103.00 by selling 6 unscented and 10 scented candles
  • 52.
  • 53.
    PROBLEM SET p. 64 #1-41 odd “Our greatest glory is not in never failing but in rising every time we fall.” - Confucius