Writing Algebraic
Expressions
Objective:
Be able to write an algebraic
expression for a word phrase or write a
word phrase for an expression.
Warm Up
Evaluate each algebraic expression for the
given value of the variables.
1.)
7x + 4 for x = 6
2.)
8y – 22 for y = 9
3.)
12x 8+
4.)
y + 3z for y = 5 and z = 6 23
y
46
50
for x = 7 and y = 4
86
Although they are closely
related, a Great Dane weighs
about 40 times as much as a
Chihuahua.
An expression for the weight of the
Great Dane could be 40c, where c is the
weight of the Chihuahua.
When solving real-world problems, you will need
to translate words, or verbal expressions, into
algebraic expressions.
Notes
In order to translate a word
phrase into an algebraic
expression, we must first
know some key word
phrases for the basic
operations.
On the back of your notes:
Addition
Subtraction
Multiplication
Division
Addition Phrases:
More than
Increase by
Greater than
Add
Total
Plus
Sum
Subtraction Phrases:
Decreased by
Difference between
Take Away
Less
Subtract
Less than*
Subtract from*
Multiplication Phrases:
Product
Times
Multiply
Of
Twice or double
Triple
Division Phrases:
Quotient
Divide
Divided by
Split equally
Notes
Multiplication expressions should
be written in side-by-side form,
with the number always in front of
the variable.
3a
2t
1.5c
0.4f
Notes
Division expressions should
be written using the fraction
bar instead of the traditional
division sign.
c
2
t
5
3
x
Examples
Addition phrases:
 3 more than x

the sum of 10 and a number c

a number n increased by 4.5
Examples
Subtraction phrases:
 a number t decreased by 4


the difference between 10 and a
number y
6 less than a number z
Examples
Multiplication phrases:
 the product of 3 and a number t

twice the number x

4.2 times a number e
Examples
Division phrases:

the quotient of 25 and a number b

the number y divided by 2

2.5 divide g
Examples
converting f feet into inches
a car travels at 75 mph for h hours
the area of a rectangle with a length
of 10 and a width of w
Examples
converting i inches into feet
the cost for tickets if you purchase 5
adult tickets at x dollars each
the cost for tickets if you purchase 3
children’s tickets at y dollars each
Examples
the total cost for 5 adult tickets and 3
children’s tickets using the dollar
amounts from the previous two
problems (problems e and f)