3. Решите уравнение: a) 10²- x²= 0 б) 9y²-81 = 0 в) (3-x)²-x(x+4,6)=9

Решим данные уравнения: a) $$10^2 - x^2 = 0 => 100 - x^2 = 0 => x^2 = 100 => x = \pm 10$$ б) $$9y^2 - 81 = 0 => 9y^2 = 81 => y^2 = 9 => y = \pm 3$$ в) $$(3 - x)^2 - x(x + 4.6) = 9 => 9 - 6x + x^2 - x^2 - 4.6x = 9 => -10.6x = 0 => x = 0$$