Answer:
[tex] {x}^{2} - 9x - 10 = 0 \\ {x}^{2} - 10x + x - 10 = 0 \\ ( {x}^{2} - 10x) + (x - 10) = 0\\ x(x - 10) + 1(x - 10) = 0 \\ (x - 10)(x + 1) = 0 \\ x - 10 + x + 1 = 0 \\ collecting \: like \: terms \: \\ x + x - 10 + 1 = 0 \\ 2x - 9 = 0 \\ 2x = 0 + 9 \\ 2x = 9 \\ x = \frac{9}{2} \\ x = 4.5[/tex]
