Factor the following:
2 a^2 - 5 a - 12
Factor the quadratic 2 a^2 - 5 a - 12. The coefficient of a^2 is 2 and the constant term is -12. The product of 2 and -12 is -24. The factors of -24 which sum to -5 are 3 and -8. So 2 a^2 - 5 a - 12 = 2 a^2 - 8 a + 3 a - 12 = a (2 a + 3) - 4 (2 a + 3):
a (2 a + 3) - 4 (2 a + 3)
Factor 2 a + 3 from a (2 a + 3) - 4 (2 a + 3):
(2 a + 3) (a - 4)
Factor the following:
2 a^2 - 5 a - 12
Factor the quadratic 2 a^2 - 5 a - 12. The coefficient of a^2 is 2 and the constant term is -12. The product of 2 and -12 is -24. The factors of -24 which sum to -5 are 3 and -8. So 2 a^2 - 5 a - 12 = 2 a^2 - 8 a + 3 a - 12 = a (2 a + 3) - 4 (2 a + 3):
a (2 a + 3) - 4 (2 a + 3)
Factor 2 a + 3 from a (2 a + 3) - 4 (2 a + 3):
(2 a + 3) (a - 4)