Answer:
(x+4)(6x^2 - 7)
Explanation:
Focus on the first 2 terms first and on the second 2 terms last:
6x^3 + 24x^2 = 6x^2(x+4)
-7x-28 = -7(x+4)
We see that the factor (x+4) is common to both pairs: common to the first 2 terms and common to the last 2 terms.
Thus,
6x³ + 24x² -7x -28 = (x+4)(6x^2 - 7(x+4)
Factoring out x+4, we get (6x^2 - 7), and so 6x³ + 24x² -7x -28 in factored form is (x+4)(6x^2 - 7).