Writing expressions

Objective:

1. Write verbal phrases and sentences as simple as algebraic expressions.

4.2 Writing Expressions• An algebraic expression is an expression that

contains a variable. For example: x – 4 or 5(n+3)

• When solving a problem you may have to translate words or phrases into algebraic expressions.

• The following chart shows the operations that may be suggested by words or phrases:Addition Subtraction Multiplication Division

plus minus Times Divided by

sum difference product quotient

More than Less than Double (× 2)Triple (× 3)

Half of (÷2)

Increased by Decreased by by Separate equally…

Gain of Less of

Twice (× 2)

per

ExamplesWrite a phrase for each

algebraic expression.

1. X + 4

2. 11(5-R)

3. 2K +6

Write an algebraic expression for each phrase.

1. Five less than a number C

2. Four times the sum of a number N and 3.

3. Six more than a number X

homework• Write a phrase for

each algebraic expression.

1. 2m

2. 6 – W

3. 2(b - 5)

4. N - 4

5. 4a + 2b

Write an algebraic expression for each phrase.

1. Fifteen increased by T

2. A number M decreased by ten

3. The product of R and eight

4. Five years more than Luis

5. Twice as many oranges.