21x2 - 19x - 12 = 0
21x2 + 37x - 12 = 0
21x2 - x + 12 = 0
21x2 + 7x - 4 = 0
Correct answer is A
Let x = \(\frac{4}{3}\), x = -\(\frac{3}{7}\)
Then 3x = 4, 7x = -3
3x - 4 = 0, 7x + 3 = 0
(3x - 4)(7x + 3) = 0
21x2 + 9x - 28x - 12 = 0
21x2 - 19x - 12 = 0