• ACTIVITY 14 Learning Targets: Lesson 14-3

Lesson 14-3
Solving Division Equations
ACTIVITY 14
continued
My Notes
Learning Targets:
Write a division equation to represent a situation.
Solve a division equation by multiplying both sides of the equation by
the same number.
x
A division equation is an equation of the form a = b, where a and b are
numbers and a ≠ 0. To solve a division equation you multiply both sides
of the equation by the denominator in order to isolate the variable.
•
•
Example D
Solve x = 9
4
Step 1: Multiply both sides by 4:
MATH TIP
Note that the equation
1 a = 12 is the same as a = 12.
2
2
Step 2:
⋅
⋅
4 x =4 9
4
Notice that 4 1 = 1 and 1 x = x.
4
Simplify both sides:
1x = 36
Solution:
⋅
⋅
x = 36
Try These D
Solve a = 8.
6
2. A candy bar costs $0.89. How much would it cost to buy 24 candy
bars? Define a variable and write an equation. Solve the equation and
check your solution.
182
Unit 3 •Expressions and Equations
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1. Emil was dividing his candy among 15 friends and himself. If each
person received 4 pieces, how many pieces of candy did Emil have to
start with? Define a variable and write an equation. Solve the
equation and check your solution.
Lesson 14-3
Solving Division Equations
ACTIVITY 14
continued
3. The cost of a ski trip is to be divided equally among 16 members of
the ski club. Each club member will pay $250. What is the total cost
of the trip? Define a variable and write an equation. Solve the
equation and check your solution.
My Notes
4. A punch recipe makes 24 servings of 6 ounces each. How many total
ounces of punch does the recipe make? Define a variable and write
an equation. Solve the equation and check your solution.
5. Make use of structure. Compare and contrast the method of
solving a multiplication equation to that of solving a division equation.
© 2014 College Board. All rights reserved.
6. Write a real-world problem that could be represented by the
equation b = 19 .
7
Activity 14 • Solving Multiplication and Division Equations
183
Lesson 14-3
Solving Division Equations
ACTIVITY 14
continued
My Notes
Check Your Understanding
7. Write a division equation for each situation.
a. Twenty-two books fit on a shelf in the library. How many books
can be displayed on 6 shelves?
b. Marguerite can save 130 pictures on a DVD. How many pictures
can be stored on 7 DVDs?
c. A pet store has 19 goldfish tanks. The store can place 12 fish in
each tank. How many goldfish can it keep?
8. Solve each equation.
a. x = 5
12
b. 16 = a
0.3
LESSON 14-3 PRACTICE
9. Write a division equation for each situation.
a. The choir is lining up on stage in three rows. There are 24 choir
members in each row. How many choir members are there?
b. Little league baseball has 12 teams with 15 children on each team.
How many children play little league baseball?
11. Make sense of problems. Write a real-world problem that can be
represented by the equation x = 16 .
6
184
Unit 3 •Expressions and Equations
© 2014 College Board. All rights reserved.
10. Solve each equation.
a. x = 26
3
b. 14 = a
9.6