Question

(x-1)(x+1) - (xla la 2 +1)

Answer 1

(a-b)(a+b)=a^2-b^2

x^2-1-x^2-1=-2

Answer 2

$(x - 1)(x + 1) - ( {x}^{2 } + 1) =$

$= x(x - 1) + (x - 1) - {x}^{2} - 1 =$

$= {x}^{2} - x + x - 1 - {x}^{2} - 1 =$

$= - 1 - 1 =$

$= - 2$