MJ3
Ch 10.3 – Writing 2-step Equations
Bellwork

Solve the following
1.
3 – 5y = -37
4 – d = 11
7 = -2n + 1
2.
3.
Assignment Review

Text p. 477 # 27 – 44
Before we begin…

Please take out your notebook and get ready
to work….
 Ok…so far we have simplified and solved 2step equations…
 In today’s lesson we will learn how to write 2step equations…
 This can have application in the real
world…for example…if you wanted to take out
a loan…you will need to be able to figure how
much and when the loan can be repaid…
10.3 Objective

Students will write and solve 2-step
equations.
Writing 2-step Equations
The key to writing 2 step equations is to
know what the words mean…
 In chapter 1 we look at English words
and their meaning in math…
 Let’s do a quick review of some of those
words…

Words that mean Add or Subtract
Addition
Subtraction
Plus
Increased by
Minus
Less
Subtract
Sum
In all
More than
Total
Less than
Decreased by
Difference
Words that mean Multiply or Divide
Multiply
Divide
Divided
Times
Rate
Multiplied
Product
Quotient
Each
An, in, or per
Of
Factors
Separate
Ratio
Writing 2-step Equations
The key or basic concept to writing 2step equations is to identify the variable
first…
 The clue to identifying the variable are
the words…”a number”
 Let’s look at some examples…

Identify the variable

Eight less than three times a number is -23

Thirteen is 7 more than twice a number

The quotient of a number and 4, decreased
by1, is equal to 5

Fifteen equals three more than six times a
number
Example


Ok…now that you have identified the
variables…lets use that to write the equations
Eight less than three times a number is -23
Three times a number is the variable…write it as
3x
 Less than means to subtract
 Is means equal to
 You get the equation
3x – 8 = - 23

Example

Thirteen is 7 more than twice a number
Twice a number is the variable write it as 2x
 More means to add
 Thirteen is means = 13
 You get the equation

13 = 2x + 7
Example

Fifteen equals three more than six times
a number
Six times a number is the variable – write it
as 6n
 More than means to add
 Fifteen equals means = 15
 You get the equation

15 = 6n + 3
Your Turn

1.
2.
3.
In the notes section of your notebook
write the sentence and then convert it
to a 2-step equation
The difference between 12 and twice a
number is 18
Three more than half a number is 15
Two more than 1/3 a number is 6
Comments





Think about this…
Yesterday you learned how to solve 2-step
equations
Today, you learned how to write them…
So naturally…we will take those two simple
tasks and add complexity by combining them
and having you write and solve 2-step
equations….
Make no mistake about it…you will be
expected to be able to write and solve 2-step
equations!
Summary
In the notes section of your notebook
summarize the key concepts covered in
today’s lesson
 Today we discussed:

Writing 2-step equations
 What do you do first?
 What is the clue?

Assignment
Text p. 480 # 7 – 18
Reminder

This assignment is due tomorrow
 You do not have to write the word problem
 Make sure that you translate each word
problem into an equation AND solve each
equation.
 You must show how you solved the
equations or no credit!
