(x+20)^1/2 -(x-1)^1/2 =3
ОДЗ: х ≥ 1
(x+20) - 2·(x-1)^1/2 ·(x+20)^1/2 + (х - 1)= 9
2х + 19 - 9 = 2·(x-1)^1/2 ·(x+20)^1/2
2х + 10 = 2·(x-1)^1/2 ·(x+20)^1/2
х + 5 = (x-1)^1/2 ·(x+20)^1/2
х² + 10х + 25 = (x-1)·(x+20)
х² + 10х + 25 = x²- х + 20х - 20
10х + 25 = 19х - 20
9х = 45
х = 5
