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An expression is NOT an equation because it DOES NOT have an
equal sign.There are 2 types of expressions.
5 + 84 Numerical3x + 10
AlgebraicNotice there are no equal signs in
these expressions so they are not equations!
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A numerical expression contains only
numbers and symbols and NO LETTERS. 5 times 3 plus 8
(5•3) + 8
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An algebraic expression contains
only numbers, symbols, and variables. It is sometimes referred to as a variable expression. The product of 3 and x 3xThe sum of m and 8 m + 8The difference of r and 2 r - 2
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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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Word Phrases for multiplication are:
The product of 5 and a number c
Seven times a number t
6 multiplied by a number d
5 • c or 5c
7 • t or 7t
6 • d or 6d
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The Placement rule for multiplication is:
The product of 5 and a number c
Seven times a number t
6 multiplied by a number d
5 • c or 5c
7 • t or 7t
6 • d or 6d
Always write the variable AFTER the number.
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Evaluate means to find the value of analgebraic expression by substitutingnumbers in for variables.
m = 26 + m ?6 + 2
8
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Evaluate means to find the value of analgebraic expression by substitutingnumbers in for variables.
r = 37 + r ?7 + 3 10
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Evaluate the variable expression when n = 6.
1) n 8 2) n 26 8
146 2
4
Evaluate just means solve by substitution.
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Evaluate the variable expression when n = 6.
Evaluate just means solve by substitution.
3) 3n 4) n63 6
18661
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Evaluate the algebraic expression when n = 8.
1) 56n
2) 20 n
568
7
20 8
12
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Evaluate the expression if a = 3 and b = 4.
1) 3a b 2) 2b a3 43
9 413
2 34 8 3
5
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Evaluate the expression if a = 3 and b = 4.
3) 2ab 4) 5 ab2 43
6 45 43 5 12
1724
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Evaluate the expression if x = 5 and y = 3.
1) 3xy
33
5
1535
2) 2 2x y2 25 3
25 9
34
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Take Out Your Study Guide!!!
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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
TYPES OF EXPRESSIONS #1
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#2
Show the substitution. Show your work down. Circle your answer.
Show your work one step at a time down. No equal signs!
Evaluate means solve.
Evaluate if x = 3 and y = 4 22 x y
22(3 4)22(7)
2(49)98