160 likes | 180 Views
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
E N D
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
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 • 18 more than a number n Answer: n+18 • 6 times a number n Answer: 6n • 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 • X+8.1 Answer: the sum of a number x and 8.1 • 10x+9 Answer: the sum of ten times a number x and 9 • n/3 Answer: the quotient of a number n and 3 • 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? 16 + 5x
Challenge • Which of the following verbal expressions represents x2+ 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? x3 – 4