Answer Key
Lesson 2.1
Practice Level B
1. domain: 0, 1, 2, 3, 4; range: 1, 2, 3, 4; is a function 2. domain: 22, 21, 0, 1;
range: 23, 21, 1, 3, 5; is not a function
3. is a function 4. is not a function
5. is a function
6.
7.
8.
9.
10.
11.
12.
13.
14.
15. linear; 3 16. not linear; 0 17. linear; 23
1
18. not linear; 2 19. not linear; } 20. linear; 1
2
21. domain: 1, 2, 3
22. range: 2.5, 3.3, 4.1, 4.2, 5.3 23. no
Answer Key
24.
25. domain: 0 ≤ t ≤ 8; range: 18 ≤ n ≤ 42 26. 27
Answer Key
Lesson 2.2
Practice Level B
9
1
3
1. 2 2. 26 3. 2} 4. 2} 5. 2 6. }
3
4
2
7. Line 2 8. Line 2 9. Line 2 10. Line 1
1
11. }; rises 12. undefined; is vertical
4
7
13. 24; falls 14. 0; is horizontal 15. 2}; falls
15
16. 0; is horizontal 17. parallel
18. perpendicular 19. neither 20. parallel
21. 27 mi/gal 22. 38 steel valves/h; yes
Answer Key
Lesson 2.3
Practice Level B
1. m 5 7, b 5 8 2. m 5 213, b 5 0
5
3. m 5 22, b 5 2 4. m 5 22, b 5 }
2
3
5. m 5 5, b 5 2 6. m 5 }, b 5 2
2
1
7. x-intercept: }, y-intercept: 21
4
8. x-intercept: 24, y-intercept: 24
9. x-intercept: 4, y-intercept: 2
2
10. x-intercept: 2}, y-intercept: 1
3
3
11. x-intercept: }, y-intercept: 22
2
12. x-intercept: 29, y-intercept: 23
13. x-intercept: 3, y-intercept: 23
14. x-intercept: 23, y-intercept: 2
5
5
15. x-intercept: 2}, y-intercept: 2}
7
14
1
1
16. x-intercept: }, y-intercept: 2}
2
4
5
5
17. x-intercept: 2}, y-intercept: 2}
6
4
8
18. x-intercept: }, y-intercept: 28
3
19.
20.
21.
22.
23.
24.
Answer Key
25.
26.
27.
28.
29.
30.
31. x 1 2y 5 48 where x is the number of hot dogs and y is the number of hamburgers.
32. 0.02x 1 0.06y 5 7000 where x is used cars sales and y is new cars sales.
1
1
33. 2} 34. 100 35. y 5 2} x 1 100
50
50
Answer Key
Lesson 2.4
Practice Level B
1. y 5 3x 2 4 2. y 5 24x 3. y 5 25
4. y 5 x 2 1 5. y 5 22x 2 1 6. y 5 4
33
7. y 5 23x 1 3 8. y 5 8x 1 }
2
9. y 5 25x 1 3 10. y 5 4x 1 11
9
1
11. y 5 23x 1 16 12. y 5 2} x 2 }
2
2
16
1
1
13. y 5 } x 2 } 14. y 5 } x 1 3
5
5
3
3
4
15. y 5 } x 2 } 16. y 5 3x 1 11
5
5
10
2
17. y 5 2} x 2 } 18. y 5 22x 1 12
3
3
7
1
19. y 5 } x 2 } 20. y 5 22x 21. y 5 1
5
5
1
22. y 5 } x 2 1 23. y 5 3.95x 1 10
2
24. p 5 0.008t 1 0.13 25. $.45
Answer Key
Lesson 2.5
Practice Level B
1. y 5 2x
1
2. y 5 2} x
2
2
3. y 5 } x
5
4
4. y 5 2} x; 24 5. y 5 4x; 12 6. y 5 7x; 21
3
1
7. y 5 5x; 15 8. y 5 2} x; 21
3
4 12
9. y 5 } x; }
7
7
3 9
1 1
2 6
10. y 5 } x; } 11. y 5 } x; } 12. y 5 } x; }
5 5
6 2
2 2
3
13. yes; 23 14. no 15. no 16. no 17. yes; }
2
3
2
18. yes; } 19. no 20. yes; y 5 } x
2
3
3
7
21. p 5 }t; 135 22. c 5 } n; $24.50
2
2
Answer Key
Lesson 2.6
Practice Level B
1. positive correlation
2. approximately no correlation
2
9
3. Sample answer: y 5 2 }x 1 }
3
4
7
6
4. Sample answer: y 5 } x 2 }
5
4
5. Sample answer:
y 5 1.2x 2 3.33
6. Sample answer:
y 5 21.8x 2 4.5
7. Sample answer: y 5 2
8.
9. Sample answer: y 5 210x 1 165.8
10. 56 thousand
Answer Key
Lesson 2.7
Practice Level B
1. a. down b. (21, 0) c. same
2. a. up b. (3, 24) c. narrower
3. a. down b. (22, 2) c. narrower
4. a. up b. (22, 8) c. narrower
5. a. down b. (21, 0) c. wider
6. a. down b. (0, 25) c. same
7. a. up b. (29, 21) c. narrower
8. a. up b. (23, 29) c. wider
9. a. down b. (1, 1) c. narrower
10.
11.
12.
13.
14.
15.
16. y 5 ⏐x 1 1⏐ 1 2 17. y 5 22⏐x 2 2⏐ 1 3
1
18. y 5 }⏐x 1 2⏐ 2 3
2
19.
20.
Answer Key
21.
22.
23.
24.
25.
26. The maximum sold is 120 in month 5.
27. The minimum sold is 15 in month 12.
Answer Key
Lesson 2.8
Practice Level B
1. yes; yes 2. yes; no 3. no; no 4. no; yes 5. yes; yes 6. yes; yes
7.
8.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22. 20x 1 10y ≥ 1500
23. (50, 65) 24. yes
25. 25x 1 20y ≤ 550
26. no 27. 10
9.
10.