Download Solving Two-Step Equations

Solving Two-Step Equations
What is a Two-Step Equation?
An equation that has 2 numbers on the
same side of the variable
3x + 7 = 13
Examples of Two-Step Equations
a) 3x – 5 = 16
b) y + 3 = 12
4
c) 5n + 4 = 6
d) n – 6 = 4
4
Steps for Solving
Two-Step Equations
1.
Solve for any ADDITION OR SUBTRACTION
on the variable side of equation by “undoing” the
operation from both sides of the equation.
2.
Solve any MULTIPLICATION OR DIVISION
from variable side of equation by “undoing” the
operation from both sides of the equation.
Opposite Operations
Addition  Subtraction
Multiplication  Division
REMEMBER,
When Solving Equations We Always
Find the variable that needs to be
alone.
Figure out what numbers we need to
get rid of.
Whatever we do to one side, we must
do to the other side to keep the
equation balanced.
Ex. 1: Solve 4x – 5 = 15
4x – 5 = 15
+5 +5
4x
= 20
4
4
x=5
WAIT!
How do you know what to get rid of
first?
Pretend it’s a Party
First your friend leaves
Then your boyfriend or girlfriend
leave
Ex. 1: Solve 4x – 5 = 15
4x – 5 = 15
+5 +5
4x
= 20
4
4
x=5
Friend,
not touching
Boyfriend or
Girlfriend,
holding hands
Try These Examples
1. 2x – 5 = 17
2. 3y + 7 = 25
3. – 2 + 5n = 38
4. 4 + 12b = 28
Try these examples!
1. x – 3 = 8
5
2. c + 4 = 9
7
3. – 6 + r = 2
3
4. 4 + d = 5
9