Can someone please help me with this expanding brackets problem ? Quick ! I will give 20 points :)

Step-by-step explanation:
[tex](x + 1)(x - 6)(x + 7)[/tex]
[tex] {x}^{2} - 6x + x - 6(x + 7)[/tex]
[tex] {x}^{3} + 7x - 6 {x}^{2} - 42x + {x}^{2} + 7x - 42[/tex]
[tex] {x}^{3} - 5x {}^{2} - 35x - 42[/tex]