Download Two-Step Equations

Two-Step
Equations
Standards
 CC.8.EE.7
variable.
Solve linear equations in one
Let’s look at pg. 171
 Let’s
walk through the activity.
 Now
let’s work through number 2.
Definitions
 Two-step
equation- an equation that
contains two operations. To solve it, you
have to undo each operation in reverse
order.
 Coefficient- a numerical factor of a term
that contains a variable.
 Reflexive Property of Equality- for any
numbers a and b, if a = b, then b = a. So
you can switch them.
Questions:
 3x
= 12
 How would you solve this equation?
 Suppose you add 2 to each side of the
equation. What is the resulting equation?
 Do the equations 3x = 12 and 3x + 2 = 14
have the same solution?
 What would you have to do to the
equation 3x + 2 = 14 to make it look like
the equivalent equation 3x = 12?
Questions
 In
an equation such as 3p + $2.50 = $7,
which operation should be undone first?
Second?
Let’s practice
 2x
+3=7
Let’s practice
 25
=¼n-3
Let’s practice
6
– 3x = 21
Let’s practice
 3x
+ 2 = 20
Let’s practice
5
+ 2n = -1
Let’s practice
 -1
= 1/2a + 9
Let’s practice
 10
– 2/3p = 52
Let’s practice
 Simon
has $150 for a class trip that costs
$320. He needs to save money for the
next 10 weeks in order to pay for the trip.
Solve the equation 10d + 150 = 320 to find
the amount of money per week Simon
must save.
Let’s practice
 Melissa
wants to put trim molding around
a rectangular table. The length of the
table is 45 inches and she has 150 inches
of trim. Solve the equation 150 = 2w + 90
to find the width of the table.