The document discusses expressions and equations. It defines an expression as not containing an equal sign, and lists two types: numerical expressions containing only numbers and symbols, and algebraic expressions containing numbers, symbols, and variables. A variable represents an unknown value and can be any letter. The document provides examples of expressions and evaluates expressions by substituting values for variables.

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2. An expression is NOT an equation
because it DOES NOT have an equal sign.
There are 2 types of expressions.
5 + 84 Numerical
3x + 10 Algebraic
Notice there are no equal signs in these
expressions so they are not equations!
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3. A numerical expression contains only
numbers and symbols and NO LETTERS.
5 times 3 plus 8
(5•3) + 8
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4. An algebraic expression contains
only numbers, symbols, and
variables. It is sometimes referred
to as a variable expression.
The product of 3 and x 3x
The sum of m and 8 m+8
The difference of r and 2 r-2
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5. What is a variable?
A variable represents an unknown value.
1) 4 + x 2) 10 – ?
3) 5y 4) 20
A variable can be any letter of the
alphabet since it represents an unknown.
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6. Word Phrases for multiplication are:
The product of 5 and a number c
5 • c or 5c
Seven times a number t
7 • t or 7t
6 multiplied by a number d
6 • d or 6d
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7. The Placement rule for multiplication is:
The product of 5 and a number c
5 • c or 5c Always
Seven times a number t write the
7 • t or 7t variable
AFTER the
6 multiplied by a number d number.
6 • d or 6d
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8. Evaluate means to find the value of an
algebraic expression by substituting
numbers in for variables.
m=2
6+m?
6+2
8
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9. Evaluate means to find the value of an
algebraic expression by substituting
numbers in for variables.
r=3
7+r?
7+3
10
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10. Evaluate the variable expression when n = 6.
1) n 8 2) n 2
6 8 6 2
14 4
Evaluate just means solve by substitution.
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11. Evaluate the variable expression when n = 6.
3) 3n 4) n
6
3 6
6
18 6
1
Evaluate just means solve by substitution.
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12. Evaluate the algebraic expression when n = 8.
1) 56 2) 20 n
n
20 8
56
8 12
7
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13. Evaluate the expression if a = 3 and b = 4.
1) 3a b 2) 2b a
3 3 4 2 4 3
9 4 8 3
13 5
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14. Evaluate the expression if a = 3 and b = 4.
3) 2ab 4) 5 ab
2 3 4 5 3 4
6 4 5 12
24 17
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15. Evaluate the expression if x = 5 and y = 3.
3x 2) x 2
y 2
1)
y 2 2
5 3
3 5 25 9
3
15 34
3
5
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16. Take Out Your Study Guide!!!
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17. #1 TYPES OF EXPRESSIONS
An expression is NOT an equation because it
does not have an equal sign. There are 2 types
of expressions.
NUMERICAL EXPRESSION: Contains only numbers and
symbols. Example: 5 • 3 + 4
ALGEBRAIC EXPRESSION: Contains numbers,
symbols, and variables. Also known as a
variable expression. Example: m + 8
A VARIABLE is a letter or symbol that represents a
number. Example: x
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18. #2
Evaluate if x = 3 and y = 4
2
2 x y Evaluate means solve.
2
2(3 4) Show the substitution.
2
2(7) Show your work down.
2(49) Circle your answer.
98
Show your work one step at a
time down. No equal signs!
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