MJ2A
Ch 7.1 – Solving Equations with
Variables on Both Sides
Bellwork
Write an equation and solve
1. Four more than twice a number is eight.
2. Five less than the quotient of a number
and three is -7
3. Nine less than six times a number is -15
•
Assignment Review
• Text p. 327 # 1 - 22
Before we begin…
• Please take out your notebook and get ready
to work…
• Ok…at this point you should be pretty
comfortable with solving one and two step
equations….in these type of equations the
variables have only been on one side of the
equation…
• In today’s lesson we will look at equations
with variables on both sides
Objective
• Students will solve equations with
variables on both sides
Solving Equations
• To solve equations with variables on
both sides the goal is to get all of the
variable to one side
• How you do that is by using the
balanced equation method and adding
or subtracting the variables…
• The strategy is to collect the variables
to the side with the largest variable…
• Let’s see what that looks like…
Example
6n – 1 = 4n – 5
Let’s analyze…
• In this case I have variables on the left and
right side of the equation…
• Of the variables 6n is the largest
variable…therefore, I will collect the variables
to the left side of the equation…
• To do that I will subtract 4n from both sides
• Once I have done that I wind up with a
simple 2-step equation…which you know how
to solve…
Example
6n – 1 = 4n – 5
-4n
-4n
2n – 1 =
–5
+1=
+1
2n
=
–4
2
n
=
=
2
–2
Subtract 4n from both sides
This is a 2 step equation
Add/Subtract first
Multiply/Divide Second
Solution
Your Turn
In the notes section of your notebook
write and solve the following:
1. 10x = 3x – 28
2. 7y – 8 = 6y + 1
3. 5n + 9 = 2n
•
Comments
• When working with these types of
problems it is important to be organized
• You ability to be organized will minimize
errors!
• Re-write the entire equation each time
you perform an operation
• Line up the equal signs and perform the
operations under the previous
operations
Summary
• In the notes section of your notebook
summarize the key concepts covered in
today’s lesson
• Today we discussed:
– Equations with variables on both sides
– How do you get the variables to one side?
– What strategy is used to decide which side
to collect the variables on?
Assignment
• Text p. 332 # 10 – 27
Reminder
– This assignment is due tomorrow
– I do not accept late assignments
– You must show your work or no credit