Name ________________________________________ Date __________________ Class__________________
LESSON
x-x
6-3
Practice C
Solving Systems by Elimination
Solve each system by elimination.
­x y 2
1. ®
¯2x y 7
________________________
­3x 4y 2
4. ®
¯6x 4y 3
________________________
­ x 6y 1
7. ®
¯2x 3y 32
________________________
­5x 2y
10. ®
¯2x 3y
48
23
________________________
­3x 2y 2
2. ®
¯3x y 10
­x y
3. ®
¯x y
_________________________
7
5
________________________
­2x 2y 14
5. ®
¯ x 4y 13
­
6. ® y x 17
¯2y 3x 11
_________________________
________________________
­ 1
°° x y 4
8. ® 2
° 1 x y 3
°¯ 3
­3x y 15
9. ®
¯2x 3y 23
_________________________
________________________
­4x 3y 9
11. ®
¯5x y 8
­3x 3y 1
12. ®
¯12x 2y 16
_________________________
________________________
13. At a bakery, Riley bought 3 bagels and 2 muffins for $7.25.
Karen bought 5 bagels and 4 muffins for $13.25. What is
____________________________________
the cost of each item?
14. A chemist has a beaker of a 3% acid solution and a beaker of
a 7% acid solution. He needs to make 75 mL of a 4% acid solution.
a. Complete the table.
Amount of Solution (mL)
Amount of Acid (mL)
3% solution
7% solution
4% solution
x
y
________
_____ y
0.04(75)
_____
x
b. Use the information in the table to write a system of
linear equations.
_____________________________________
c. Solve the system of equations to find how much he
will use from each beaker.
_________________________________________________________________________________________
© Houghton Mifflin Harcourt Publishing Company
139
Holt McDougal Coordinate Algebra
Practice C
6-3 SOLVING SYSTEMS BY
ELIMINATION
1. (2, 4)
2. (3, 1)
3. (0, 8)
4. (2, 1)
§1
·
5. ¨ , 2 ¸
2
©
¹
6. (6, 2)
1. 0y; 3x; 3; 3; 2; 2; 2; 2; 2; 12; 4; 2; 4
7. (0.8, 0.2)
8. (8, 12)
2. 2y; 7; 0y; 3; 3; 1; 1; 3; 3; 3; 9; 9; 9;
2; 2; 2; 1; 3; 1
9. (6, 8)
Practice A
3. 2; 4; 16; 5; 10; 5; 10; 5; 5; 2; 2; 2; 2; 2;
10; 2; 2; 5; 2; 5
10. 11 and 28
11. 12 quarters
12. $12.00
Review for Mastery
1. (2, 3)
2. (7, 9)
3. (4, 1)
4. (17, 7)
5. (3, 6)
6. (1, 7)
3; y
1, z
4
2. x
1; y
4, z
3
3. x
2; y
4. x
2; y
13, z
6. (8, 1)
7. 3 and 4
1. 4y
24; 6; 2; 2; 6
2. 6; 2; 34; 2x
5
8, z
5. (6, 2)
Practice B
Challenge
1. x
4. (3, 4)
4
14; 7; 4; 7; 4
3. (2, 3)
4. (9, 1)
5. (4, 6)
§ 1 ·
6. ¨ , 3 ¸
© 2 ¹
7. (4, 1)
§ 1
·
8. ¨ , 2 ¸
5
©
¹
9. $22
Problem Solving
10. 7 Gala apples; 12 Granny Smith apples
1. 3 quarters,
5 dimes
Practice C
2. 3 months;
1. (3, 1)
2. (2, 4)
3. (1, 6)
§ 1 1·
4. ¨ , ¸
©3 4¹
5. (3, 4)
6. (9, 8)
7. (13, 2)
8. (6, 1)
9. (2, 9)
10. (10, 1)
$155
3. 12 turkey burgers,
9 beef hamburgers
4. used CD $4.50,
used DVD $6.50
5. B
6. H
7. A
8. H
13. bagel: $1.25; muffin: $1.75
Reading Strategies
1. y
5 x or y
14. 75; 0.03; 0.07
x 5
­ x y 75
®
¯0.03 x 0.07 y
2. The first equation is already solved for y.
3. The solution of a system must satisfy
both equations.
4. (6, 4)
§5 ·
12. ¨ , 2 ¸
©3 ¹
11. (3, 7)
3
56.25 mL of the 3% solution; 18.75 mL
of the 7% solution
5. (3, 5)
Review for Mastery
1. (3, 14)
2. (4, 1)
3. (6, 18)
4. (4, 14)
© Houghton Mifflin Harcourt Publishing Company
A23
Holt McDougal Coordinate Algebra