14.
16.
x² +17x + 72
(x + 9)(x + 8)
x + 9 = 0 ∧ x + 8 = 0
x = -9 ∧ x = -8
17.
4v² - 16v + 7
Break the expression into groups
(4v² - 2v) + (-14v + 7)
Factor out 2v from 4v² - 2v and factor out -7 from -14v + 7
2v (2v - 1) - 7 (2v - 1)
(2v - 1) (2v - 7)
2v - 1 = 0 ∧ 2v - 7 = 0
2v = 1 ∧ 2v = 7
∧ 
18.
n² - 16n + 64
(n - 8) (n - 8)
n = 8 ∧ n = 8
19.
6t² - 54
Factor out the common term 6
6 (t² - 9)
Factor (t² - 9)
6 (t² - 9)
6 (t + 3) (t - 3)
t = -3 * 6 ∨ t = 3 * 6
t = -18 ∨ t = 18
20.
y² - 121
(y - 11) (y + 11)
y = 11 ∧ y = -11
16.
x² +17x + 72
(x + 9)(x + 8)
x + 9 = 0 ∧ x + 8 = 0
x = -9 ∧ x = -8
17.
4v² - 16v + 7
Break the expression into groups
(4v² - 2v) + (-14v + 7)
Factor out 2v from 4v² - 2v and factor out -7 from -14v + 7
2v (2v - 1) - 7 (2v - 1)
(2v - 1) (2v - 7)
2v - 1 = 0 ∧ 2v - 7 = 0
2v = 1 ∧ 2v = 7
18.
n² - 16n + 64
(n - 8) (n - 8)
n = 8 ∧ n = 8
19.
6t² - 54
Factor out the common term 6
6 (t² - 9)
Factor (t² - 9)
6 (t² - 9)
6 (t + 3) (t - 3)
t = -3 * 6 ∨ t = 3 * 6
t = -18 ∨ t = 18
20.
y² - 121
(y - 11) (y + 11)
y = 11 ∧ y = -11