214 1) 3x²+x−12 = 1; 3) 2x-1/x+3 = 4;

1. $$3^{x^2+x-12} = 1$$

   $$3^{x^2+x-12} = 3^0$$

   $$x^2 + x - 12 = 0$$

   $$D = 1 + 4 \cdot 12 = 49$$

   $$x_1 = \frac{-1 + 7}{2} = 3$$

   $$x_2 = \frac{-1 - 7}{2} = -4$$

2. $$2^{\frac{x-1}{x+3}} = 4$$

   $$2^{\frac{x-1}{x+3}} = 2^2$$

   $$\frac{x-1}{x+3} = 2$$

   $$x - 1 = 2(x+3)$$

   $$x - 1 = 2x + 6$$

   $$x = -7$$

Ответ: 3 и -4; -7