Решите уравнение: a) $$(4x - 3)(4x + 3) - (4x - 1)² = 3x$$; б) $$16с² - 49 = 0$$.

a) $$(4x - 3)(4x + 3) - (4x - 1)^2 = 3x$$ $$16x^2 - 9 - (16x^2 - 8x + 1) = 3x$$ $$16x^2 - 9 - 16x^2 + 8x - 1 = 3x$$ $$8x - 10 = 3x$$ $$5x = 10$$ $$x = 2$$ б) $$16c^2 - 49 = 0$$ $$(4c)^2 - 7^2 = 0$$ $$(4c - 7)(4c + 7) = 0$$ $$4c - 7 = 0$$ или $$4c + 7 = 0$$ $$4c = 7$$ или $$4c = -7$$ $$c = \frac{7}{4}$$ или $$c = -\frac{7}{4}$$ **Ответы:** a) **$$x = 2$$** б) **$$c = \frac{7}{4}$$ или $$c = -\frac{7}{4}$$**