Решите уравнения пожалуйста

Решите задачу:

$a) \sqrt{x-2} = 3 ( \sqrt{x-2}) ^2 = 3^2 x-2 = 9 x = 11$

$b) \sqrt{12-x} - \sqrt{x-2} = 0 (\sqrt{12-x})^2 - (\sqrt{x-2})^2 = 0^2 12 - x - x -2 = 0 10 - 2x = 0 2x = 10 x = 5$

$c) \sqrt{x} + \sqrt{x - 5} = 6 (\sqrt{x})^2 + (\sqrt{x - 5})^2 = 6^2 x + x - 5 = 36 2x - 5 = 36 2x = 41 x = 20,5$

$d) \sqrt{x^2 - 16} = x + 2 (\sqrt{x^2 - 16})^2 = (x + 2)^2 x^2 - 16 = x^2 + 4x + 4 x^2 - x^2 - 4x = 16 + 4 -4x = 20 x = -5$