Answer:
[tex]12x^{2} -11x-5[/tex]
Step-by-step explanation:
1) Distribute
[tex]4x(3x-1)-2(3x+1)-(x+3)\\12x^{2} -4x-2(3x+1)-(x+3)[/tex]
2) Distribute
[tex]12x^{2} -4x-2(3x+1)-(x+3)\\12x^{2} -4x-6x-2-(x+3)[/tex]
3) Distribute
[tex]12x^{2} -4x-6x-2(x+3)\\12x^{2} -4x-6x-2-x-3[/tex]
4) Subtract the numbers
[tex]12x^{2} -4x-6x-2-x-3\\12x^{2} -4x-6x-5-x[/tex]
5) Combine like terms
[tex]12x^{2} -4x-6x-5-x\\12x^{2} -11x-5[/tex]