Question

${x}^{2} - 1 - 2a - {a}^{2}$
factorize it​

Answer 1

x²-(1+2a+a²)
x²-(1+a)²
[x-(1+a)] [x+(1+a)]
(x-1-a)(x+1+a)

Tip: Use an app called photomath. It’s really useful, especially for these kind of questions :)