Answer:
[tex] {12x}^{4} + {24x}^{3} - {20x}^{2} + 4x[/tex]
Step-by-step explanation:
[tex]4x(3x^{3} + 6x^{2} - 5x + 1) \\ = 12x^{4} + {24x}^{3} - {20x}^{2} + 4x[/tex]