Chapter 1 Section 1.1 Objective: to write algebraic expressions

Vocabulary Quantity: anything that can be measured or counted. Variable: a symbol, usually a letter, that represents the value(s) of a variable quantity Algebraic expression: a mathematical phrase that includes one or more variables Numerical expression: a mathematical phrase involving numbers and operation symbols, but no variables

Operation words PhraseSymbol Sum+ Difference- ProductX Quotient÷ Less than- More than+

Writing Expressions with Addition and Subtraction Example 1: 32 more than a number n N+32 Example 2: 58 less than a number n N-58

Writing Expressions with Multiplication and Division Example 3: 8 times a number n 8xn, 8●n, 8n Example 4: the quotient of a number n and 5 n÷5,

TRY THESE a.18 more than a number n Answer: n+18 b.6 times a number n Answer: 6n c.The quotient of 18 and a number n Answer: 18÷n

Writing Expressions with two operations Example 5: 3 more than twice a number x 3+2x Example 6: 9 less than the quotient of 6 and a number x 6/x-9 Example 7: the product of 4 and the sum of a number x and 7 4(x+7)

TRY THESE 8 less than the product of a number x and 4 Answer: 4x-8 Twice the sum of a number x and 8 Answer: 2(x+8) The quotient of 5 and the sum of 12 and a number x Answer: 5/12+x

Using Words for an Expression Example 8: Expression-3x OR 3●x Words- three times a number x OR The product of 3 and a number x

TRY THESE a.X+8.1 Answer: the sum of a number x and 8.1 b.10x+9 Answer: the sum of ten times a number x and 9 c.n/3 Answer: the quotient of a number n and 3 d.5x-1 Answer: five times a number x less 1

Try These Which of the following expressions represents 7 times a number decreased by 13? 7x - 13

Try These Which one of the following expressions represents 28 less than three times a number? 3x - 28

Try These Which of the following verbal expressions represents 2x + 9? 9 increased by twice a number

Try These Which of the following expressions represents the sum of 16 and five times a number? x

Challenge Which of the following verbal expressions represents x 2 + 2x? the sum of a number squared and twice a number

Challenge 2 Which of the following expressions represents four less than the cube of a number? x 3 – 4