Presentation on theme: "Pre Test Translate each word into a mathematical operation."— Presentation transcript:
1 Pre Test Translate each word into a mathematical operation. +1) increase+6) plus−2) decrease−7) difference÷3) more than+8) quotient+4) less than−9) sum•5) product•10) timesWrite and answer the following problems.11) Simplify. −4212) Write 2y • 2y • 2y in exponential form.
2 1-1 Variables and Expressions You would be wise to listen carefully and take notes!Be smart -correct your odd homework problems after you complete them!Algebra Glencoe McGraw-Hill Linda Stamper
3 In algebra, variables are symbols used to represent unspecified numbers or values. Any letter may be used as a variable.An expression that represents a particular number is called a numerical expression.Example:An algebraic expression consists of one or more constants and variables along with one or more arithmetic operations.constants - numbersvariables - lettersoperations - addition, subtraction, multiplication and divisionExample of an algebraic expression: 3x + 2
4 In algebraic expressions, a raised dot or parentheses are often used to indicate multiplication as the symbol x can be easily mistaken for the variable x. Here are some ways to represent the product of x and y.Use good form in an answer!In each expression, the quantities being multiplied are called factors, and the result is called the product.
5 An expression like 43 is called a power. base exponentor powerword form: four to the third powerfour cubedfactor form: 4 • 4 • 4evaluated form: 64To evaluate an expression means to find its value.The word power can also refer to the exponent.
6 Writing Algebraic Expressions In English there is a difference between a phrase and a sentence. Phrases are translated into mathematical expressions. Sentences are translated into equations or inequalities.PhraseThe sum of 6 and a number6 + nSentenceThe difference of a number and three is five.n – 3 = 5SentenceSeven times a number is less than 50.7n < 50When choosing a variable for an unknown, it may be helpful to select a letter that relates to the unknown value (for example: let a represent age). If a variable is given use it!Sentences must have a verb!Sentences must have a verb!
7 Would you say 5 notebooks or notebooks 5? The product of five and a number5nThe product of a number and fiveWould you say 5 notebooks or notebooks 5?5nWrite your answer in good form - the number comes before a variable in a term involving multiplication.
8 Use a fraction bar to designate division! Write an algebraic expression for each word phrase.a. The difference of a number and 7n – 7b. 32 increased by a number32 + nc. 25 less than a number25n–d. 10 less the product of 5 and a number cubed10 – 5n3e. The quotient of a number and six.n6Use a fraction bar to designate division!
9 Did you use a fraction bar to designate division? Example 1 Write the phrase as an algebraic expression.a. 11 greater than a numberDid you use a fraction bar to designate division?n + 11b. a number subtracted from 1515 – nc. The sum of a number and 30n + 30d. Maria’s age minus 27a – 2718ne. The quotient of 18 and a numberf. The sum of a number and ten, divided by two.
10 Example 2 Write the phrase as an algebraic expression. a. eight more than a numbern + 8b. seven less the product of 4 and a number x7 – 4xc. n cubed divided by 2d. 9 more than the quotient of b and 5e. one third the original area of af. thirteen less than a numbern - 13
11 Write in exponential form (as a power). Example 3Example 4Example 5y • y • y • y3x • 3x • 3x • 3x5 • 5 • 5y453(3x)4Evaluate.Example 6Example 7Example 82 • 2 • 2 • 25 • 5 • 5-32(-3)216125-99Must have parentheses!A power applies only to what is directly in front of it.
12 Pre TestWrite and answer the following problems in your spiral notebook.1) Simplify. −422) Write 2y • 2y • 2y in exponential form.−16(2y)3− 4 • 4A power applies only to what is directly in front of it.The 2y must be in parentheses!