Transcript Solving Equations with Addition and Subtraction

Draw a line
to make a
column (on
either side of
paper)
Joe Smith
1/23/12
Period 3
Notes: Solving One Step Equations by Adding/Subtracting
1.
Erase!! Do
not scratch
out your
mistakes
Opposite
operation
x5  7
5 5
x0  2
x2
Solve
Write vocab
words in the
column
Summary
Do opposite
operation on both
sides
Heading: Include
your first and last
name, the date,
and your class
period number
Write the title of the
notes on the top line
* Addition &
Subtraction
* Multiplication &
Division
Draw line at
the end of
your notes,
write the
word
summary
and answer
summary
questions
Objective
The student will be able to:
solve equations using addition and
subtraction.
Revised from PP Designed by Skip Tyler, Varina High School
PROPERTIES OF EQUALITY
• Addition property of equality
– If a = b, then a + c = b + c
• Subtraction property of equality
– If a = b, then a – c = b – c
• Multiplication property of equality
– If a = b, then ac = bc
• Division property of equality
– If a = b and c ≠ 0, then
a b

c c
1) Solve r + 16 = -7
Think of this equation as a balance scale.
Whatever you do to one side has to be done to the
other to keep it balanced!
1.
2.
1) Solve r + 16 = -7
Draw the line
- 16 -16
Do the opposite
operation on both
r
=
-23
sides
3.
4.
Simplify vertically
Check your answer
-23 + 16 = -7
YOU TRY!!
2) Solve 8 = m - 3
1.
2.
3.
4.
m=5
m = 11
m = 24
m = 8/3
Answer Now
1.
2.
2) Solve 8 = m - 3
+3
+3
Draw the line
11= m
Do the opposite
3.
4.
operation on both
sides
Simplify vertically
Check your answer
8 = 11 - 3
eliminate double signs
y + (-3) = 8
is rewritten as
y–3=8
p – (-5) = 6
is rewritten as
p+5=6
As a general rule, replace “+ (- )” with “–” and “– (- )” with “+”.
This will make things less confusing in the future!
3) Solve y + (-3) = 7
1.
2.
3.
4.
Draw the line
Do the opposite
operation on both
sides
Simplify vertically
Check your answer
y–3 =7
+ 3 +3
y
= 10
10 + (-3) = 7
4) Solve. -x - (-2) = 1
1. Draw the line
2. Do the opposite
operation on both
sides
3. Simplify vertically
4. Check your answer
-x + 2 = 1
-2 -2
-1x = -1
-1
-1
x
= 1
-(1) + 2 = 1
27 10  37
27  x  50
 27
 27
x  23
27  60  87
GROUP ACTIVITY
• EACH GROUP WILL GET AN EQUATION
• THERE ARE PROBLEMS HANGING UP AROUND
THE ROOM
• AS A GROUP, FIND THE PROBLEM THAT GOES
WITH YOUR EQUATION. TAKE IT BACK TO YOUR
GROUP.
• AS A GROUP, COMPLETE THE PROBLEM LIKE WE
DID ON THE LAST SLIDE. UNDERLINE THE KEY
WORDS AND SHOW ALL WORK.
Game
• http://www.math-play.com/One-StepEquation-Game.html
Summary
• How can you tell if you need to use addition or
subtraction to solve an equation?
• Solve the following problem using table below to
show your work, explain the steps and identity the
property used. -x – (-5) = -10.
STEP
-x – (-5) = -10
Given
PROPERTY