Unit 3 Vocabulary: Expressions and Equations

1)VARIABLE: A variable is a symbol, usually a letter, that represents one or more numbers

  • Example: x is a variable in 2x +1

2)NUMERICAL EXPRESSION: An expression that contains only numbers and operations.

  • Example: 12 + 6 or 18 + 3 – 4

3)VALUE OF NUMERICAL EXPRESSION: The result or the answer from evaluating the expression.

  • Example: 6 is the result of 2 + 4. So, 6 is the value of the numerical expression

4)SUM: The result when two or more numbers are ADDED

  • Example: 2 + 3 + 5 = 10; 10 is your sum

5)DIFFERENCE: The result when you SUBTRACT two numbers.

  • Example: 10 – 2 = 8; 8 is the difference of 10 and 2

6)PRODUCT: The result from multiplying two or more numbers.

  • Example: 3 x 5 = 15; 15 is your product

7)QUOTIENT: The result from dividing two numbers.

  • Example: 20/5 = 4; 4 is your quotient

8)ALGEBRAIC EXPRESSION: An expression that contains numbers, variables, and operations.

  • Example: 2x + 4 (This is different from a numerical expression because it contains the variable x)

9)EQUIVALENT EXPRESSION: Expressions that are the same, even though they may look a little different. If you plug in the same variable value into equivalent expressions, they will each give you the same value when you simplify.

  • Example: 2x + 4 and 2(x+2) are equivalent expressions
  • If x = 3, then 2x + 3 = 2(3) + 4 = 6 + 4 = 10
  • If x = 3, then 2(x+2) = 2(3+2) = 2(5) = 10
  • Since 10 = 10, these expressions are equivalent (equal)

10) TERM: Each part of an expression.

  • Example: In the algebraic expression: 2x + 3y + 5

2x , 3y, and 5 are three different terms.

11) LIKE TERMS: Terms of an algebraic expression that have the same variables raised to the same exponents.

  • Example: In the expression 2x + 5y + 3x + 2x2 + 4 + 3
  • 2x and 3x are like terms because they both have the variable x
  • 4 and 3 are like terms because they are both constants
  • 5y does not have a like term in this expression
  • 2x2 does not have a like term in this expression

12)COEFFICIENT: The number found in front of the variable and indicates MULTIPLICATION.

  • Example: In the term 3x + 5, 3 is the coefficient. It indicates that you are multiplying 3 and x.

13) CONSTANT: A term that has a number but no variable.

  • Example: In the expression 2x + 8, the term 8 is a constant.

14)EQUATION: A mathematical sentence sentence that uses an equal sign (=) to show that two expressions are equal

  • Example: 4x = 16 or a + 7 = 21

15)INVERSE OPERATIONS: Operations that “undo” each other.

  • Example: Addition/Subtraction or Multiplication/Division

Unit 3 Vocabulary

WORD / DEFINITION / EXAMPLE
VARIABLE
NUMERICAL
EXPRESSION
VALUE OF
NUMERICAL
EXPRESSION
SUM
DIFFERENCE
PRODUCT
QUOTIENT
ALGEBRAIC
EXPRESSION
EQUIVALENT EXPRESSION
TERM
LIKE TERMS
COEFFICENT
CONSTANT
EQUATION
INVERSE OPERATIONS