8th Chapter 1 Lesson 7

Transparency 7:

Transparency 7 Click the mouse button or press the Space Bar to display the answers.

Splash Screen:

Splash Screen

Example 7-1b:

Example 7-1b Objective Write algebraic expressions and equations from verbal phrases and sentences

Example 7-1b:

Example 7-1b Vocabulary Defining a variable To choose a variable and an unknown quantity for the variable to represent Five years older than her brother Let a represent her brother’s age

Lesson 7 Contents:

Lesson 7 Contents Example 1 Write an Algebraic Expression Example 2 Write an Algebraic Expression Example 3 Write an Algebraic Equation Example 4 Write an Equation to Solve a Problem

Example 7-1a:

Example 7-1a Write double the price of a loaf of bread as an algebraic expression. 1/4 Answer: 2 p Determine the process word(s) “Double” means multiply by 2 Define the variable Let p represent the price of the bread p 2  p Remember: when multiplying a number by a variable, the number goes first

Example 7-1b:

Example 7-1b Write triple the cost of a cup of coffee as an algebraic expression. Answer: 3 c 1/4

Example 7-2a:

Example 7-2a Write stalks of celery are divided into 4 portions as an algebraic expression. Let c represent the stalks of celery. Answer: 2/4 Define the variable c Determine the process word(s) Put the division sign using the fraction bar The denominator will be what you are dividing into 4

Example 7-2b:

Example 7-2b Write pies are divided into 8 portions as an algebraic expression. Answer: 2/4

Example 7-3a:

Example 7-3a Write the price of a book plus $5 shipping is $29 as an algebraic equation. Let p represent the price of the book. 3/4 Define the variable p Determine the process word(s) “plus” refers to addition so put an addition sign p + Write how much will be added p + 5

Example 7-3a:

Example 7-3a Write the price of a book plus $5 shipping is $29 as an algebraic equation. Answer: 3/4 p + 5 “is” refers to equals so write an equals sign p + 5 = Determine what the expression will equal p + 5 = 29

Example 7-3b:

Example 7-3b Write the price of a toy plus $6 shipping is $35 as an algebraic equation. Answer: 3/4

Example 7-4a:

Example 7-4a NUTRITION A particular box of oatmeal contains 10 individual packages. If the box contains 30 grams of fiber, write an equation to find the amount of fiber in one package of oatmeal. Determine what to do to the variable (process) Let f represent the grams of fiber per package. 4/4 Define the variable f Amount of fiber in 10 packages refers to “multiply” by 10 10  f

Example 7-4a:

Example 7-4a NUTRITION A particular box of oatmeal contains 10 individual packages. If the box contains 30 grams of fiber, write an equation to find the amount of fiber in one package of oatmeal. 4/4 Remember: 10 packages in a box 10  f A box contains 30 grams of fiber This would refer to equal 30 10  f = 30 Answer: 10f = 30 Remember when multiplying a number with a variable the number comes first

Example 7-4b:

Example 7-4b NUTRITION A particular box of cookies contains 10 servings. If the box contains 1,200 Calories, write an equation to find the number of Calories in one serving of cookies. Answer: * 4/4

End of Lesson 7:

End of Lesson 7 Assignment Lesson 1:7 Writing Expressions & Equations 8 - 30 All