Решите неравенство:

1) log7 (2-5x) ≤ 2

2) (1/5) ^3x+12 = 1/27

1) log7_ (2 - 5x) ≤ log7_49;

{2-5x > 0; { - 5x > - 2; {x < 0,4;

2-5x ≤ 49; - 5x ≤ 47; x ≥ - 9,4 x ∈ [-9,4; 0,4).

2) (1/3) ^ (3x+12) = 1/27;

(1/3) ^ (3x+12) = (1/3) ^3;

3x + 12 = 3;

3x = - 9;

x = - 3