1. 10/21/08 Solve with multiplication or division (2-12 B) #26
Warm-up: Solve the following A. B. C. D. E. F. G.
x + 5 = x – 34 = = x – 39
Assignment:
(2-12) B evens or odds AND (2-12) puzzle all
Show all steps on graph paper in required format.
Quiz corrections are due tomorrow for retakes.
Math binder scores will be collected tomorrow for lessons #11- #21

2. 10/21/08 Solve with multiplication or division (2-12 B) #26
Warm-up A. B. C. D. F. G.
x + 5= x – 34 = = x – 39 E.
X = 4
x = 106
163 = x
Assignment:
(2-12) B evens or odds AND (2-12) puzzle all
Show all steps on graph paper in required format.
Quiz corrections are due tomorrow for retakes.
Math binder scores will be collected tomorrow for lessons #11- #21

3. • 2 5 10 = 10 5 2 ÷ = Solving Equations by Multiplying or Dividing
Course 2
2-12
Solving Equations by Multiplying or Dividing
Like addition and subtraction, multiplication
and division are inverse operations. They
“undo” each other. 2 • 5 10 = 10 5 2 ÷ =

4. Additional Example 1: Solving an Equation by Multiplication
Course 2
2-12
Solving Equations by Multiplying or Dividing
Additional Example 1: Solving an Equation by Multiplication
Solve the equation = 13. Check your answer. h 2 h 2
= 13 h 2
(2)
= 13(2)
Think: h is divided by 2, so
multiply both sides by 2 to
isolate h.
h = 26
Check h 2
= 13 26 2 ?
= 13
Substitute 26 for h.
13 = 13 ?
26 is a solution. 

5. MULTIPLICATION PROPERTY OF EQUALITY
Course 2
2-12
Solving Equations by Multiplying or Dividing
MULTIPLICATION PROPERTY OF EQUALITY
You can multiply
both sides of an
equation by the
same number,
and the statement
will still be true.
3 · 4 =
x = y
2 · 3 · 4 = 2 · 12
zx = zy
6 · 4 =
If a variable is divided by a number, you can
often use multiplication to isolate the variable.
Multiply both sides of the equation by the
number.

6. Insert Lesson Title Here
Course 2
2-12
Solving Equations by Multiplying or Dividing
Insert Lesson Title Here
Try This: Example 1 x 5
Solve the equation = 30. Check your answer. x 5
= 30 x 5
(5)
= 30(5)
Think: x is divided by 5, so
multiply both sides by 5 to
isolate x.
x = 150
Check x 5
= 30
150 5 ?
= 30
Substitute 150 for x.
30 = 30 ? 
150 is a solution.

7. Additional Example 2: Solving an Equation by Division
Course 2
2-12
Solving Equations by Multiplying or Dividing
Additional Example 2: Solving an Equation by Division
Solve the equation 51 = 17x. Check your answer.
51 = 17x
Think: x is multiplied by 17,
so divide both sides by 17 to
isolate x.
51 = 17x 17 17
3 = x
Check
51 = 17x
51 = 17(3) ?
Substitute 3 for x.
51 = 51 ? 
3 is a solution.

8. DIVISION PROPERTY OF EQUALITY
Course 2
2-12
Solving Equations by Multiplying or Dividing
DIVISION PROPERTY OF EQUALITY
You can divide
both sides of an
equation by the
same nonzero
number, and the
statement will still
be true.
5 · 6 = 30
5 · 6 3 = 30
5 · 6
= 10
5 · 2 = 10 x z
x = y y =
z ≠ 0
You cannot divide by 0.
Remember!

9. Insert Lesson Title Here
Course 2
2-12
Solving Equations by Multiplying or Dividing
Insert Lesson Title Here
Try This: Example 2
Solve the equation 76 = 19y. Check your answer.
76 = 19y
Think: y is multiplied by 19,
so divide both sides by 19 to
isolate y.
76 = 19y 19 19
4 = y
Check
76 = 19y
76 = 19(4) ?
Substitute 4 for y.
76 = 76 ? 
4 is a solution.

10. Additional Example 3 Continued
Course 2
2-12
Solving Equations by Multiplying or Dividing
Additional Example 3 Continued
Beats in 10s times = beats per minutes
b · =
Think: b is multiplied
by 6, so divide both
sides by 6 to isolate b.
6b = 78
6b = 78
b = 13
Trevor’s heart beats 13 times 10 seconds.

11. Insert Lesson Title Here
Course 2
2-12
Solving Equations by Multiplying or Dividing
Insert Lesson Title Here
Lesson Quiz: Part 1
Solve the equation. Check your answer.
1. 12 = 4x
2. 18z = 90
3. 12 =
= 12y 5.
x = 3
z = 5 x 4
x = 48
y = 70 h 22
= 9
h = 198

12. Show all steps on graph paper in required format.
10/21/08 Solve with multiplication or division (2-12 B) #26
Show all steps on graph paper in required format.
(2-12) B evens or odds
AND
(2-12) puzzle all
Quiz corrections are due tomorrow for retakes.
Math binder scores will be collected tomorrow for lessons #11- #21