1-3
Exercises
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MT10 1-3
Exercises 1–14, 15, 23, 25
GUIDED PRACTICE
See Example 1
Use properties to determine whether the expressions are equivalent.
1. 10( d 4 ) and 10d 40
2. 4 b 8 and b 12
3. 0 ( x 8 ) and x
See Example 2
4.
7( 8a ) and 56a
5. Sports Antonio collects sports cards. He has 19 packs of football cards,
23 packs of baseball cards, and 7 packs of basketball cards. Use properties
and mental math to answer each question.
a. How many packs of cards are in Antonio’s collection?
b. If each pack contains 6 cards, what is the total number of cards in
Antonio’s collection?
See Example 3
Find a counterexample to disprove each conjecture.
6. The Commutative Property is true for division.
7. The quotient of two whole numbers is always a whole number.
INDEPENDENT PRACTICE
See Example 1
Use properties to determine whether the expressions are equivalent.
9. ( g 1 ) 16 and 16g
8. 0( 5m ) and 5m
10. 20 t 0 and t 20
See Example 2
11. 12( 2 m ) and 24 m
12. Money Jackie mowed 15 lawns in June, 23 lawns in July, and 15 lawns
in August. Use properties and mental math to answer each question.
a. How many lawns did Jackie mow over the summer?
b. Jackie put $4 in her savings account for each lawn she mowed.
How much money did Jackie save over the summer by mowing lawns?
See Example 3
Find a counterexample to disprove each conjecture.
13. The Associative Property is true for subtraction.
14. The sum of two whole numbers is always greater than either number.
PRACTICE AND PROBLEM SOLVING
Extra Practice
See page EP2.
Complete each equation. Then tell which property is represented.
15.
1 24
17. 12( 40 3 ) 12( 40 )
19. 38 38
16. 15 3 (3)
15
18. ( 15 15 ) 2 15 (
20. 14(
2)
) 0
21. Geometry The perimeter of a rectangle is equal to 2( ᐉ w ), where
ᐉ is the length of the rectangle and w is the width. Write at least two
expressions equivalent to 2( ᐉ w ). Use properties to justify your answer.
22. Life Science Find a counterexample to disprove the conjecture, “The
number of legs of any animal is a multiple of 4.”
16
Chapter 1 Principles of Algebra