Hi, I am not sure how the 1/2x^-1/2 was factorized out in this numerator that was derived from the quotient rule. Can some please explain.

= (x^2 + 1) (1/2x^-1/2) – x^1/2 (2x)

=1/2x^-1/2 (x^2 +1 – 4x^2)

I understand how factorization works but I am not sure what happened in this case.

Thank you.