Answer Key - CK-12 Chapter 01 Algebra I Concepts
Answer Key - CK-12 Chapter 01 Algebra I Concepts
Answer Key - CK-12 Chapter 01 Algebra I Concepts
1 – Equations and FunctionsAnswer Key
1.1 Definition of Variable
Answers
1. (2)(11x)
2. 1.35y
3. (3)( 41 )
4. 41 z
5. m = .25q + .10d
6. m = .25q + .10d + .01p
7. (7 + 6)x
8. 20x − 4
9. m = 10.25h − 4
10. i = 2000
c
11.
CK12 Algebra I Concepts 1
Chapter 1 – Equations and FunctionsAnswer Key
1.2 Expressions with One or More Variables
Answers
1. 2(− 3) + 3(2) = 0
2. 4(5) + (− 4) = 16
3. 5(− 3)(5) − 2(2) =− 79
2(−3) −6
4. 2
5 ( 4) = 9 =− 3
−−
3(2)
5. = 6
=− 1 21
−4 −4
(−3)−4(2)
6. 3(5)+2(−4) =− 11
7
7. 1
=− 1
−3+2
(−3)(2) −6 3
8. 5(−4) = −20
= 10
9. C = 2000 + 3(1000) = $5, 000
10. C = 2000 + 3(2000) = $8, 000
11. C = 2000 + 3(2500) = $9, 500
12.
CK12 Algebra I Concepts 2
Chapter 1 – Equations and FunctionsAnswer Key
1.3 Algebra Expressions with Exponents
Answers
1. 8(− 1)3 =− 8
5(−1)2 5
2. 6(−3)3
= −162
3. 3(− 3)2 − 5(4)2 = 27 − 80 =− 53
4. (− 1)2 − (2)2 =− 3
(−3)3 +(4)3 37
5. (−3)3 −(4)3
=− 91
6. 2(− 1)3 − 3(− 1)2 + 5(− 1) − 4 =− 14
7. 4(4)3 + 3(4)2 − 4 + 2 = 302
8. 3 + ( 13)2 = 28
9
−
9. V = 4(2)(10 − 2)2 = 512 in3
10. V = 4(3)(10 − 3)2 = 588 in3
11.
CK12 Algebra I Concepts 3
Chapter 1 – Equations and FunctionsAnswer Key
1.4 Order of Operations
Answers
1. a) 2(5)2 = 50
b) 3(5)2 + 2(5) + 1 = 86
2. 75
3. (1 − 2)2 = 1
4. 3
5. 3+7
7−12 =− 2
6. (4 − 1)2 + 32 (2) = 27
7. (5 − 2)×(6 − 5) + 2 = 5
8. 12÷4 + 10 − 3×3 + 7 = 11
9. (22 − 32 − 5)×(3 − 5) = 30
10. 12 − [(8 − 4)×5) =− 8
11. (250)2 + 2(250) − (250(− 120)) = 93, 000
2
12. (0.02(− 0.025) − (0.025)4 ) = 0.000000250 = 2.50×10−7
13.
CK12 Algebra I Concepts 4
Chapter 1 – Equations and FunctionsAnswer Key
1.5 Algebra Expressions with Fraction Bars
Answers
2(3+(2−1))
1. 4−(6+2) − (3 − 5) = 0
4+7(3) 12−3(2)
2. 9−4 + 2 = 8
2
(22 +5)
3. 52 −42
÷(2 + 1) = 3
6(12)
4. 6+12 = 4
2+32
5. 3−2 = 11
4(2) 8
6. 9(2)2 −3(2)+1
= 31
7. 42 2
1+(−2) + 1−1(−2) =− 47
3
4(3)(2)(5)
8. =− 24
22 −32
(−1)2 −(3)2
9. (−1)(3)−2(−1)(3—1) =− 58
10. 2502 + 2(250) − (250)(− 120) = 93, 000
2
11. (0.02(− 0.025) − (0.025)4 ) = 2.5×10−7
1 3
2 + 2 −(−1)
12. ( 2 )( 2 )+( 23 )(−1)+( 21 )(−1)
1 3 =− 12/5
(3+(−5))2 4
13. 4(32 )−(−5)2
=− 11
4−(−2)3 (4+(−2))2 21
14. 43 −(−2)
+ 4+(−2)4
= 55
CK12 Algebra I Concepts 5
Chapter 1 – Equations and FunctionsAnswer Key
1.6 Patterns and Expressions
Answers
1. p = 20d
2. $200
3. $220
4. c = 24 − e
5. c = 24 − 9 = 15
6. c = 24 − 9 − 3 = 12
7. 7x = 35 : x = 5
8. 3x + 15 = 24 : x = 3
9. 2x = 5y − 3 : 3y = 15 : y = 5, x = 11
p
12. 3 = p − 6 : p = 9
CK12 Algebra I Concepts 6
Chapter 1 – Equations and FunctionsAnswer Key
13. s = 5q
14. 70 = 5q : q = 14
15. 83 = 5q : q = 17
16. 80%
17. .25(w + a) = a : a = 1, w = 3
19. s = 2f : f + 9 = 2s : f = 3, s = 6
20.
a. 1:30 pm
b. 6:24pm
c. 24 mins
d. 30 mins
21. .8x = 120 : $150
22. $50
CK12 Algebra I Concepts 7
Chapter 1 – Equations and FunctionsAnswer Key
1.7 Words that Describe Patterns
Answers
CK12 Algebra I Concepts 8
Chapter 1 – Equations and FunctionsAnswer Key
1.8 Checking Solutions to Equations
Answers
1. 4(− 3) + 3 =− 9 : Y ES
3 4 1
2. 4(3) + 2 = 23 : Y ES
3. 2.5(2) − 10.0 =− 5.0 : Y ES
4. 2(5 − 2(− 5)) = 20 − 2(− 5 − 1) : N O
5. 5(10) − 7 = 43 : Y ES
6. 3( 32 ) + 5 = 7 : Y ES
7. − 39 (10) =− 30 : Y ES
8. 2( 21 ) = 1.5 − 21 : Y ES
9. 0.5(1 − 2(0.5) = 6 + 6(4(0.5) − 3) : Y ES
10. 0.27l = f : 0.27l = 15, 000 : l = 55, 555.55
CK12 Algebra I Concepts 9
Chapter 1 – Equations and FunctionsAnswer Key
1.9 Checking Solutions to Inequalities
Answers
1. 2((12) + 6)≤8(12) : Y ES
2. 1.4(− 9) + 5.2 > 0.4(− 9) : N O
3. − 25 (40) + 1
2 <− 18 : Y ES
4. 80≥10(3(.4) + 2) : Y ES
5. 1000 + 0.06x≥1200 + 0.05(x − 2000) : x ≥10, 000
6.
a. c = 10
b. c = 5 + 0.05(m − 60)
c. c = 0.10m
7. 10 < 5 + 0.05(m − 60) : m > 160
8. 10 < 0.1m : m > 100
9. 5 + 0.05(m − 60) < 0.10m : m > 40
10. m > 160
11. 40 < m≤160
12. m≤40
13. Plan C
14. Plan A: $10, Plan B: $5, Plan C: $3
CK12 Algebra I Concepts 10
Chapter 1 – Equations and FunctionsAnswer Key
1.10 Domain and Range of a Function
Answers
12.
Heigh 1 2 3 4 5 6
t
Area 4 8 1 1 2 2
2 6 0 4
13.
x 1 0 1 2 3 4 5
CK12 Algebra I Concepts 11
Chapter 1 – Equations and FunctionsAnswer Key
CK12 Algebra I Concepts 12
Chapter 1 – Equations and FunctionsAnswer Key
1.11 Functions that Describe Situations
Answers
1. f (x) = x 2
2. f (x) = 15 + 5x
24
3. f (x) = 2x
4. f (x) = x − 1
x
5. f (x) = 2
6. f (h) = 40 + 25h
7. f (3) = 40 + 25(3) : f (3) = 115
8. 3(f (1)) = 3(40 + 25(1)) = 195
9. f (b) = 12.50b
10. p(b) = 12.50b − 2500
11. 12.50b = 2500 : b = 200
12. 12.50b = 2550 : b = 204
CK12 Algebra I Concepts 13
Chapter 1 – Equations and FunctionsAnswer Key
1.12 Functions on a Cartesian Plane
Answers
1. 5.
6.
a. (6, 4)
b. (7, 6)
c. (8, 2)
d. (4, 7)
e. (5, 0)
7.
CK12 Algebra I Concepts 14
Chapter 1 – Equations and FunctionsAnswer Key
8.
9.
10.
CK12 Algebra I Concepts 15
Chapter 1 – Equations and FunctionsAnswer Key
CK12 Algebra I Concepts 16
Chapter 1 – Equations and FunctionsAnswer Key
1.13 Graphs of Functions Based on Rules
Answers
1. Y = 20x
2.
CK12 Algebra I Concepts 17
Chapter 1 – Equations and FunctionsAnswer Key
CK12 Algebra I Concepts 18
Chapter 1 – Equations and FunctionsAnswer Key
3.
4.
CK12 Algebra I Concepts 19
Chapter 1 – Equations and FunctionsAnswer Key
CK12 Algebra I Concepts 20
Chapter 1 – Equations and FunctionsAnswer Key
5.
6.
CK12 Algebra I Concepts 21
Chapter 1 – Equations and FunctionsAnswer Key
CK12 Algebra I Concepts 22
Chapter 1 – Equations and FunctionsAnswer Key
7.
8.
CK12 Algebra I Concepts 23
Chapter 1 – Equations and FunctionsAnswer Key
CK12 Algebra I Concepts 24
Chapter 1 – Equations and FunctionsAnswer Key
9.
10.
CK12 Algebra I Concepts 25
Chapter 1 – Equations and FunctionsAnswer Key
1.14 Function Rules based on Graphs
Answers
1. Apx 62.5 years
2. Apx 69 years
3. Apx 73 years
4. Apx 76 years
5. Apx $19,000
6. Apx $55,500
7. Apx $10,500
8. Apx $30,500
9. y =− 23 x + 9
10. y = ∣ 2x ∣
11. y = √x
CK12 Algebra I Concepts 26
Chapter 1 – Equations and FunctionsAnswer Key
1.15 Algebraic Functions
Answers
1. Yes, function
2. No, not a function
3. Yes, function
4. No, not a function
5. Yes, function
6. Yes, function
7. Yes, function
8. No, not a function
9. Yes, function
10. No, not a function
CK12 Algebra I Concepts 27
Chapter 1 – Equations and FunctionsAnswer Key
1.16 ProblemSolving Models
Answers
1. $37.71
2. $42,857.14
3. $545
4. $89.29
5. $45.25
6. $750
7. 316 minutes
8.
a. 8 rides
b. $31.50
9. $219.65
10. 86%
11. It is a 306090 triangle
CK12 Algebra I Concepts 28
Chapter 1 – Equations and FunctionsAnswer Key
12. $96
CK12 Algebra I Concepts 29
Chapter 1 – Equations and FunctionsAnswer Key
13. 7 cups
14.
a. She makes $15 per lawn
b. The bike costs $100
15.
a. Jared collects 3+3(2)+12=21 pieces
b. The three kids together collect 21+23+23=67 pieces
16. 5 blocks are missing
17. 40 minutes
18. The home team wins by 1, Karen owes Chase 9($0.50)=$4.50
19. Kelley scores 37 points
20. 24 people ( $350 1
$15 = 23 3 , but they can’t charge 1/3 of a person)
21.
26(2)
a. 8 = 6.5 halfpound containers (7, assuming the store only sells full containers)
b. 6($4.80) + 7($2.80) = $48.40
CK12 Algebra I Concepts 30
Chapter 1 – Equations and FunctionsAnswer Key
1.17 Comparison of ProblemSolving Models
Answers
1. 35 nickels and 5 dimes
2. 4 tenfoot plots and 10 twelvefoot plots
3. 23 squares in the 12 th diagram
4. They need a threebedroom house
5. 7 guests (Jaden + 5 guests = $120, 2 more guests = $180 total)
6. 44 students and 156 general admission
7. 6 weeks
8. $0.50
9.
a. It will hold 6 and burst with 7
b. 4 smoothies
10. $240
11. 5 ½ hours
12. 4 hours
13.
a. 210 visitors
b. 1,110 visitors
14. 36 square feet
15. 18 points
16. Janet is 6, and Mark is 9
17. Jane scored 6 points, and Russell scored 4 points
18.
a. First pod will arrive first, on the 9th
of June
b. Second pod will arrive two days later on the 11 th
c. The second pod will catch the first pod on the second day
d. 30 miles
CK12 Algebra I Concepts 31
Chapter 1 – Equations and FunctionsAnswer Key
CK12 Algebra I Concepts 32