Answer:
2x(2x + 7)(3x - 1).
Explanation:
12x^3 + 38x^2 - 14x
= x(12x^2 + 38x - 14)
= 2x(6x^2 + 19x - 7)
To factor the expression in the parentheses we need 2 numbers whose product is (6 * -7) = - 42 and whose sum = +19.
These are +21 and - 2.
So, we write:
6x^2 - 2x + 21x - 7
= 2x(3x - 1) + 7(3x - 1)
= (2x + 7)(3x - 1)
So, the answer is 2x(2x + 7)(3x - 1).