2. Expressions
You are familiar with the following type of
numerical expressions:
12 + 6
3 (12)
6 (3 + 2)
15 - 4 (6)
3. What is a constants?
In the expression 12 + B, 12 is a constant
AA constantconstant is a number of its own that isis a number of its own that is
used to represent a known quantity.used to represent a known quantity.
4. What is a variable?
In the expression 12 + B, the letter “B” is a
variable.
AA variablevariable is a letter or symbol thatis a letter or symbol that
represents an unknown value.represents an unknown value.
5. What are coefficients?
A coefficient is the number multiplied by the
variable in an algebraic expression.
Algebraic Expression Coefficient
6m + 5 6
8r + 7m + 4 8, 7
14b - 8 14
6. What is a term?
A term is the name given to a number, a
variable, or a number and a variable
combined by multiplication or division.
Algebraic Expressions Terms
a + 2 a, 2
3m + 6n - 6 3m, 6n, - 6
7. Algebraic Expressions
When variables are used with other numbers,
parentheses, or operations, they create an
algebraic expression.
a + 2
(a) (b)
3m + 6n - 6
8. What are constants?
• A constant is a number that cannot change
its value.
In the expression: 5x + 7y - 2
the constant is - 2.
9. Evaluation
• Evaluate an algebraic expression –
To find the value of an algebraic
expression by substituting numbers
for variables.
• m + 8 m = 2 2 + 8 = 10
• r – 3 r = 5 5 – 3 = 2
10. Write Algebraic Expressions
for These Word Phrases
• A number s plus 2
• A number decrease by 1
• 31 less than a number
• A number b increased by 7
• The sum of a number & 6
• 9 more than a number
s + 2
k - 1
x - 31
13. Write an Algebraic Expression
for These Situations
• Scott’s brother is 2 years younger than
Scott
• The sum of two numbers is 12
• The difference between two numbers is 5
s - 2
v + c = 12
m – n = 5
14. Which is the coefficient in the term
11mn?
A.
B.
C.
D.
m
n
11
m,n
15. Which is the variable in the term
215pq?
A.
B.
C.
D.
215
p
Pq
215p
q
