Unit 1
Lesson 1: Variables and Expressions
Algebra 1 CP
Mrs. Mongold
A few things to remember…
 Multiplication in Algebra is represented in the following ways
 The multiplication dot ∙
 By writing things next to each other, 4x, means 4 times x
 Using parentheses, 5(xy), means 5 times xy
 A variable is a letter used to represent a value
 The number in the monomial 4x is called the coefficient
 In the monomial 3x2 the three is the coefficient, the x is the
base, and the 2 is the exponent.
 (3x)2 and 3x2 are not the same thing
A few things to remember…
 Multiplication in Algebra is represented in the following ways
 The multiplication dot ∙
 By writing things next to each other, 4x, means 4 times x
 Using parentheses, 5(xy), means 5 times xy
 A variable is a letter used to represent a value
 The number in the monomial 4x is called the coefficient
 In the monomial 3x2 the three is the coefficient, the x is the
base, and the 2 is the exponent.
 (3x)2 and 3x2 are not the same thing
A few things to remember…
 Multiplication in Algebra is represented in the following ways
 The multiplication dot ∙
 By writing things next to each other, 4x, means 4 times x
 Using parentheses, 5(xy), means 5 times xy
 A variable is a letter used to represent a value
 The number in the monomial 4x is called the coefficient
 In the monomial 3x2 the three is the coefficient, the x is the
base, and the 2 is the exponent.
 (3x)2 and 3x2 are not the same thing
A few things to remember…
 Multiplication in Algebra is represented in the following ways
 The multiplication dot ∙
 By writing things next to each other, 4x, means 4 times x
 Using parentheses, 5(xy), means 5 times xy
 A variable is a letter used to represent a value
 The number in the monomial 4x is called the coefficient
 In the monomial 3x2 the three is the coefficient, the x is the
base, and the 2 is the exponent.
 (3x)2 and 3x2 are not the same thing
A few things to remember…
 Multiplication in Algebra is represented in the following ways
 The multiplication dot ∙
 By writing things next to each other, 4x, means 4 times x
 Using parentheses, 5(xy), means 5 times xy
 A variable is a letter used to represent a value
 The number in the monomial 4x is called the coefficient
 In the monomial 3x2 the three is the coefficient, the x is the
base, and the 2 is the exponent.
 (3x)2 and 3x2 are not the same thing
A few things to remember…
 Multiplication in Algebra is represented in the following ways
 The multiplication dot ∙
 By writing things next to each other, 4x, means 4 times x
 Using parentheses, 5(xy), means 5 times xy
 A variable is a letter used to represent a value
 The number in the monomial 4x is called the coefficient
 In the monomial 3x2 the three is the coefficient, the x is the
base, and the 2 is the exponent.
 (3x)2 and 3x2 are not the same thing
A few things to remember…
 Multiplication in Algebra is represented in the following ways
 The multiplication dot ∙
 By writing things next to each other, 4x, means 4 times x
 Using parentheses, 5(xy), means 5 times xy
 A variable is a letter used to represent a value
 The number in the monomial 4x is called the coefficient
 In the monomial 3x2 the three is the coefficient, the x is the
base, and the 2 is the exponent.
 (3x)2 and 3x2 are not the same thing
A few things to remember…
 Multiplication in Algebra is represented in the following ways
 The multiplication dot ∙
 By writing things next to each other, 4x, means 4 times x
 Using parentheses, 5(xy), means 5 times xy
 A variable is a letter used to represent a value
 The number in the monomial 4x is called the coefficient
 In the monomial 3x2 the three is the coefficient, the x is the
base, and the 2 is the exponent.
 (3x)2 and 3x2 are not the same thing
Definitions
 Algebraic Expression: a mathematical sentences
expressing numbers and variables using mathematical
operations
 Variable: Any letter used to represent unspecified numbers
or values
 Factors: Any numbers or variables being multiplied
together
 Product: The result of multiplying factors together
Definitions
 Algebraic Expression: a mathematical sentences
expressing numbers and variables using mathematical
operations
 Variable: Any letter used to represent unspecified numbers
or values
 Factors: Any numbers or variables being multiplied
together
 Product: The result of multiplying factors together
Definitions
 Algebraic Expression: a mathematical sentences
expressing numbers and variables using mathematical
operations
 Variable: Any letter used to represent unspecified numbers
or values
 Factors: Any numbers or variables being multiplied
together
 Product: The result of multiplying factors together
Definitions
 Algebraic Expression: a mathematical sentences
expressing numbers and variables using mathematical
operations
 Variable: Any letter used to represent unspecified numbers
or values
 Factors: Any numbers or variables being multiplied
together
 Product: The result of multiplying factors together
To write an algebraic expression
 1. Read the written sentence
 2. Label any given information with a variable or operation
sign
 3. Rewrite
 See summer review packet for key words
To write an algebraic expression
 1. Read the written sentence
 2. Label any given information with a variable or operation
sign
 3. Rewrite
 See summer review packet for key words
To write an algebraic expression
 1. Read the written sentence
 2. Label any given information with a variable or operation
sign
 3. Rewrite
 See summer review packet for key words
To write an algebraic expression
 1. Read the written sentence
 2. Label any given information with a variable or operation
sign
 3. Rewrite
 See summer review packet for key words
Examples from summer packet
 1. The sum of 9 and a number
 9+x
 OR
 x+9
Examples from summer packet
 1. The sum of 9 and a number
 9+x
 OR
 x+9
 2. The difference of a number cubed and twelve
 x3 - 12
 2. The difference of a number cubed and twelve
 x3 - 12
 3. A number decreased by 8
 x-8
 3. A number decreased by 8
 x-8
 4. Three less than 5 times a number
 5x-3
 4. Three less than 5 times a number
 5x-3
 5. One-third the square of b
1 2
 b
3
 5. One-third the square of b
1 2
 b
3
 6. The product of four and x increased by y
 4x + y
 6. The product of four and x increased by y
 4x + y
 7. The quotient of a number and negative 5
𝑥

−5
 7. The quotient of a number and negative 5
𝑥

−5
 8. A number to the power of five less seven
 x5 - 7
 8. A number to the power of five less seven
 x5 - 7
 9. Twice the sum of 15 and a number
 2(15 + x)
 9. Twice the sum of 15 and a number
 2(15 + x)
 10. The quotient of three and the sum of a number and 11
3

𝑥+11
 10. The quotient of three and the sum of a number and 11
3

𝑥+11
Homework
 Blue packet page 8/ 1-26 NO CALCULATORS