[tex]x(x + 6) - 6(x - 1) - x {}^{2} \\ x {}^{2} + 6x - 6x + 6 - x {}^{2} \\ 6[/tex]
[tex](2x + 1)(4x) - 8x \times (x + 1) \\ (2x + 1) \times 4x - 8x {}^{2} - 8x \\ 8x {}^{2} + 4x - 8x {}^{2} - 8x \\ - 4x[/tex]
[tex](4x {}^{2} )(5x) \\ 4x {}^{2} + 5x \\ 20x {}^{3} [/tex]
