Download presentation
Presentation is loading. Please wait.
Published byJulie Miller Modified over 8 years ago
1
2-1 Variables and Expressions Course 1 Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day 2-1 Variables and Expressions Course 1 Warm Up Warm Up
2
2-1 Variables and Expressions Course 1 Warm Up Simplify. 1. 4 + 7 3 1 2. 87 15 5 3. 6(9 + 2) + 7 4. 35 7 5 24 84 73 25
3
2-1 Variables and Expressions Course 1 Problem of the Day How can the digits 1 through 5 be arranged in the boxes to make the greatest product? 4 3 1 5 2
4
2-1 Variables and Expressions Course 1 Learn to identify and evaluate expressions.
5
2-1 Variables and Expressions Course 1 Vocabulary variable constant algebraic expression
6
2-1 Variables and Expressions Course 1 A variable is a letter or symbol that represents a quantity that can change. A constant is a quantity that does not change.
7
2-1 Variables and Expressions Course 1 An algebraic expression contains one or more variables and may contain operation symbols. So p 7 is an algebraic expression. Algebraic Expressions NOT Algebraic Expressions 150 + y85 ÷ 5 35 w + z 10 + 3 5 To evaluate an algebraic expression, substitute a number for the variable and then find the value.
8
2-1 Variables and Expressions Course 1 Evaluate the expression to find the missing values in the table. Additional Example 1A: Evaluating Algebraic Expressions Substitute for y in 5 y. y 5 y 16 27 35 80 y = 16; 5 16 = 80 135 175 27135 35175 y = 27; 5 = y = 35; 5 = The missing values are 135 and 175.
9
2-1 Variables and Expressions Course 1 Evaluate the expression to find the missing values in the table. Additional Example 1B: Evaluating Algebraic Expressions z z 5 + 4 2 20 45 60 20 z = 20; 20 5 + 16 = 20 z = 45; __ 5 + 16 = __ z = 60; __ 5 + 16 = __ 25 28 45 25 60 28 The missing values are 25 and 28. Substitute for z in z 5 + 4 2.
10
2-1 Variables and Expressions Course 1 Check It Out: Example 1A Evaluate the expression to find the missing values in the table. Substitute for x in x 9. x x 9 18 36 54 2 x = 18; 18 9 = 2 4 6 4 54 6 x = 36; 9 = x = 54; 9 = 36 The missing values are 4 and 6.
11
2-1 Variables and Expressions Course 1 Evaluate the expression to find the missing values in the table. Check It Out: Example 1B z 8 z + 2 3 7 9 11 64 z = 7; 8 7 + 8 = 64 z = 9; 8 __+ 8 = __ z = 11; 8 __ + 8 = __ 80 96 980 1196 The missing values are 80 and 96. Substitute for z in 8 z + 2 3.
12
2-1 Variables and Expressions Course 1 You can write multiplication and division expressions without using the symbols and . Instead of... You can write... x 3 x 3 35 ÷ y x(3) 3x3x 35 y When you are multiplying a number times a variable, the number is written first. Write “3x” not “x3.” Read 3x as “three x.” Writing Math
13
2-1 Variables and Expressions Course 1 A rectangle is 4 units wide. How many square units does the rectangle cover if it is 3, 4, 5, or 6 units long? Additional Example 2: Evaluating Expressions with Two Variables Make a table to help you find the number of square units for each length. 3 x 4 = square units 20 16 lwl x w 3412 44 54 64 The rectangle will cover 12, 16, 20, or 24 square units. 4 x 4 = square units 5 x 4 = square units 6 x 4 = square units 12 16 20 24
14
2-1 Variables and Expressions Course 1 A rectangle is 3 units wide. How many square units does the rectangle cover if it is 2, 3, 4, or 5 units long? Check It Out: Example 2 Make a table to help you find the number of square units for each length. 2 x 3 = square units 12 9 lwl x w 236 33 43 53 The rectangle will cover 6, 9, 12, or 15 square units. 3 x 3 = square units 4 x 3 = square units 5 x 3 = square units 6 9 12 15
15
2-1 Variables and Expressions Course 1 1. Evaluate the expression to find the missing values in the table. Lesson Quiz 2. A rectangle is 6 units wide. How many square units does the rectangle cover if it is 2, 3, 4, or 5 units long? 95 44 20 12 lwl x w 26 36 46 56 18 24 30 xx 2 – 5 10 7 5
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.