Question

(x-1)(x+1)-x(x+2)=x-10

Answer 1

[tex] x^{2} - 1 - x^{2} - 2x = x - 10 -1 - 2x = x - 10 3x = 9; x = 3[/tex]

Answer 2

$\displaystyle (x-1)(x+1)-x(x+2)=x-10 \\ x^2-1-x^2-2x=x-10 \\ x^2-x^2-2x-x=-10+1 \\ -3x=-9 \\ x= \frac{-9}{-3} \\ \boxed{x=3}$