Tìm x biết: √25x = 35, √4x <= 162, 3√x = √12, 2√x >= 10, √(x^2 - 9) - 3√(x - 3) = 0, √(x^2 - 4) - 2√(x + 2) = 0

65. Tìm x, biết:
a) √25x = 35; b) √4x <= 162; c) 3√x = √12; d) 2√x >=10
66. Tìm x, biết:
a) √(x² - 9) - 3√(x - 3) = 0
b) √(x² - 4) - 2√(x + 2) = 0