Tolong jawab dan Kasih penjelasannya ya guys

Misal : m = √x => m^2 = x
Lim {√(16x - 5√x + 7) - √(16x - 7√x - 9)}
= Lim {√(16m^2 - 5m + 7) - √(16m^2 - 7m - 9)}
(b - q)/2√a = (-5 - (-7))/2√16 = 2/8 = 1/4