1) log 1/3 (2x-4) = -2 2) log2 (x2-x-4) = 3 3) lg9x2-x+8) = 1

1. log 1/3 (2x - 4) = - 2;

(1/3) ^-2 = 2x - 4;

2x - 4 = 9;

2x = 9 + 4;

2x = 13;

x = 6,5.

Ответ: 6,5.

2. log 2 (x^2 - x - 4) = 3;

2^3 = x^2 - x - 4;

8 = x^2 - x - 4;

x^2 - x - 12 = 0;

D = 1 + 48 = 49;

x = (1 + - 7) / 2;

x1 = 4, x2 = - 3.

3. lg 9 (x2 - x + 8) = 1;

9^1 = x^2 - x + 8;

x^2 - x + 8 = 9;

x^2 - x - 1 = 0;

D = 1 + 4 = 5;

x = (1 + - sqrt5) / 2.