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7.3 Factor Trinomials of the Form ax 2 +bx+c

Leading coefficients other than one, cracked by organized trial and error or by the 'ac' grouping method, after any common factor is stripped off.

Elementary Algebra 2e, 7.3 Factor Trinomials of the Form ax 2 +bx+c

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73 exercises

7.3 Exercise 1

Before you get started, take this readiness quiz.

Find the GCF of 45p2and30p645 p^{2} \text{and} 30 p^{6}.
If you missed this problem, review the reference.

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7.3 Exercise 2

Multiply (3y+4)(2y+5)\left(3 y + 4\right) \left(2 y + 5\right).
If you missed this problem, review the reference.

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7.3 Exercise 3

Combine like terms 12x2+3x+5x+912 x^{2} + 3 x + 5 x + 9.
If you missed this problem, review the reference.

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7.3 Exercise 4

Identify the best method to use to factor each polynomial.

  1. ⓐ 6y2−726 y^{2} - 72
  2. ⓑ r2−10r−24r^{2} - 10 r - 24
  3. ⓒ p2+5p+pq+5qp^{2} + 5 p + p q + 5 q
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7.3 Exercise 5

Identify the best method to use to factor each polynomial:

  1. ⓐ 4y2+324 y^{2} + 32
  2. ⓑ y2+10y+21y^{2} + 10 y + 21
  3. ⓒ yz+2y+3z+6y z + 2 y + 3 z + 6
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7.3 Exercise 6

Identify the best method to use to factor each polynomial:

  1. ⓐ ab+a+4b+4a b + a + 4 b + 4
  2. ⓑ 3k2+153 k^{2} + 15
  3. ⓒ p2+9p+8p^{2} + 9 p + 8
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7.3 Exercise 7

Factor completely: 2n2−8n−422 n^{2} - 8 n - 42.

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7.3 Exercise 8

Factor completely: 4m2−4m−84 m^{2} - 4 m - 8.

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7.3 Exercise 9

Factor completely: 5k2−15k−505 k^{2} - 15 k - 50.

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7.3 Exercise 10

Factor completely: 4y2−36y+564 y^{2} - 36 y + 56.

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7.3 Exercise 11

Factor completely: 3r2−9r+63 r^{2} - 9 r + 6.

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7.3 Exercise 12

Factor completely: 2t2−10t+122 t^{2} - 10 t + 12.

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7.3 Exercise 13

Factor completely: 4u3+16u2−20u4 u^{3} + 16 u^{2} - 20 u.

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7.3 Exercise 14

Factor completely: 5x3+15x2−20x5 x^{3} + 15 x^{2} - 20 x.

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7.3 Exercise 15

Factor completely: 6y3+18y2−60y6 y^{3} + 18 y^{2} - 60 y.

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7.3 Exercise 17

Factor completely: 2a2+5a+32 a^{2} + 5 a + 3.

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7.3 Exercise 18

Factor completely: 4b2+5b+14 b^{2} + 5 b + 1.

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7.3 Exercise 20

Factor completely: 8x2−14x+38 x^{2} - 14 x + 3.

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7.3 Exercise 21

Factor completely: 10y2−37y+710 y^{2} - 37 y + 7.

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7.3 Exercise 23

Factor completely: 8a2−3a−58 a^{2} - 3 a - 5.

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7.3 Exercise 24

Factor completely: 6b2−b−156 b^{2} - b - 15.

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7.3 Exercise 26

Factor completely: 18x2−3x−1018 x^{2} - 3 x - 10.

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7.3 Exercise 27

Factor completely: 30y2−53y−2130 y^{2} - 53 y - 21.

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7.3 Exercise 29

Factor completely: 15n3−85n2+100n15 n^{3} - 85 n^{2} + 100 n.

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7.3 Exercise 30

Factor completely: 56q3+320q2−96q56 q^{3} + 320 q^{2} - 96 q.

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7.3 Exercise 32

Factor: 6x2+13x+26 x^{2} + 13 x + 2.

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7.3 Exercise 33

Factor: 4y2+8y+34 y^{2} + 8 y + 3.

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7.3 Exercise 35

Factor: 20h2+13h−1520 h^{2} + 13 h - 15.

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7.3 Exercise 36

Factor: 6g2+19g−206 g^{2} + 19 g - 20.

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7.3 Exercise 38

Factor: 10t2+19t−1510 t^{2} + 19 t - 15.

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7.3 Exercise 39

Factor: 3u2+8u+53 u^{2} + 8 u + 5.

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7.3 Exercise 41

Factor: 16x2−32x+1216 x^{2} - 32 x + 12.

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7.3 Exercise 42

Factor: 18w2−39w+1818 w^{2} - 39 w + 18.

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7.3 Exercise 43

Identify the best method to use to factor each polynomial.

  1. ⓐ 10q2+5010 q^{2} + 50
  2. ⓑ a2−5a−14a^{2} - 5 a - 14
  3. ⓒ uv+2u+3v+6u v + 2 u + 3 v + 6
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7.3 Exercise 45

Identify the best method to use to factor each polynomial.

  1. ⓐ x2+4x−21x^{2} + 4 x - 21
  2. ⓑ ab+10b+4a+40a b + 10 b + 4 a + 40
  3. ⓒ 6c2+246 c^{2} + 24
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7.3 Exercise 47

Factor completely.

5x2+35x+305 x^{2} + 35 x + 30

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7.3 Exercise 49

Factor completely.

2z2−2z−242 z^{2} - 2 z - 24

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7.3 Exercise 51

Factor completely.

7v2−63v+567 v^{2} - 63 v + 56

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7.3 Exercise 53

Factor completely.

p3−8p2−20pp^{3} - 8 p^{2} - 20 p

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7.3 Exercise 55

Factor completely.

3m3−21m2+30m3 m^{3} - 21 m^{2} + 30 m

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7.3 Exercise 57

Factor completely.

5x4+10x3−75x25 x^{4} + 10 x^{3} - 75 x^{2}

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7.3 Exercise 59

Factor.

2t2+7t+52 t^{2} + 7 t + 5

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7.3 Exercise 61

Factor.

11x2+34x+311 x^{2} + 34 x + 3

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7.3 Exercise 63

Factor.

4w2−5w+14 w^{2} - 5 w + 1

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7.3 Exercise 65

Factor.

6p2−19p+106 p^{2} - 19 p + 10

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7.3 Exercise 67

Factor.

4q2−7q−24 q^{2} - 7 q - 2

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7.3 Exercise 69

Factor.

4p2+17p−154 p^{2} + 17 p - 15

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7.3 Exercise 71

Factor.

16x2−32x+1616 x^{2} - 32 x + 16

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7.3 Exercise 73

Factor.

30q3+140q2+80q30 q^{3} + 140 q^{2} + 80 q

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7.3 Exercise 75

Factor.

5n2+21n+45 n^{2} + 21 n + 4

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7.3 Exercise 77

Factor.

9z2+15z+49 z^{2} + 15 z + 4

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7.3 Exercise 79

Factor.

4k2−16k+154 k^{2} - 16 k + 15

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7.3 Exercise 81

Factor.

5s2−9s+45 s^{2} - 9 s + 4

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7.3 Exercise 83

Factor.

6y2+y−156 y^{2} + y - 15

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7.3 Exercise 85

Factor.

2n2−27n−452 n^{2} - 27 n - 45

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7.3 Exercise 87

Factor.

3x2+5x+43 x^{2} + 5 x + 4

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7.3 Exercise 89

Factor.

60y2+290y−5060 y^{2} + 290 y - 50

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7.3 Exercise 91

Factor.

48z3−102z2−45z48 z^{3} - 102 z^{2} - 45 z

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7.3 Exercise 93

Factor.

16s2+40s+2416 s^{2} + 40 s + 24

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7.3 Exercise 95

Factor.

48y2+12y−3648 y^{2} + 12 y - 36

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7.3 Exercise 97

Factor.

12y2−29y+1412 y^{2} - 29 y + 14

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7.3 Exercise 99

Factor.

a2−a−20a^{2} - a - 20

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7.3 Exercise 101

Factor.

6n2+5n−46 n^{2} + 5 n - 4

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7.3 Exercise 103

Factor.

2p2+4p+32 p^{2} + 4 p + 3

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7.3 Exercise 105

Factor.

13z2+39z−2613 z^{2} + 39 z - 26

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7.3 Exercise 107

Factor.

x2+3x−28x^{2} + 3 x - 28

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7.3 Exercise 109

Factor.

3p2+21p3 p^{2} + 21 p

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7.3 Exercise 111

Factor.

6r2+30r+366 r^{2} + 30 r + 36

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7.3 Exercise 113

Factor.

24n2+20n+424 n^{2} + 20 n + 4

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7.3 Exercise 115

Factor.

x2+2x−24x^{2} + 2 x - 24

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7.3 Exercise 117

Height of a toy rocket The height of a toy rocket launched with an initial speed of 80 feet per second from the balcony of an apartment building is related to the number of seconds, t, since it is launched by the trinomial −16t2+80t+96−16 t^{2} + 80 t + 96. Completely factor the trinomial.

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7.3 Exercise 119

List, in order, all the steps you take when using the “ac” method to factor a trinomial of the form ax2+bx+c.a x^{2} + b x + c .

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7.3 Exercise 121

What are the questions, in order, that you ask yourself as you start to factor a polynomial? What do you need to do as a result of the answer to each question?

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Adapted from Elementary Algebra 2e © 2020 Rice University. Licensed under CC BY 4.0. Source: Elementary Algebra 2e. Imported at revision 77a933c.