Решите неравенства3x-12≤05 (3+x) - 2x≤82x-2 (6+2x) >2x+7x (1+5x) - 5x (x+14) ≤2 (x-7)

Найдем решения неравенств.

1) 3 * x - 12 ≤ 0;

3 * x < 12;

x < 12/3;

x < 4.

2) 5 * (3 + x) - 2 * x ≤ 8;

Скобки раскроем.

5 * 3 + 5 * x - 2 * x < = 8;

15 + 5 * x - 2 * x < = 8;

15 + 3 * x < = 8;

3 * x < = 8 - 15;

3 * x < = - 7;

x < = - 7/3.

3) 2 * x - 2 * (6 + 2 * x) > 2 * x + 7;

2 * x - 2 * 6 - 2 * 2 * x > 2 * x + 7;

2 * x - 12 - 4 * x > 2 * x + 7;

-2 * x - 12 > 2 * x + 7;

-2 * x - 2 * x > - 7 - 12;

-4 * x > - 19;

x < 19/4.

4) x * (1 + 5 * x) - 5 * x * (x + 14) ≤ 2 * (x - 7);

x + 5 * x^2 - 5 * x^2 - 70 * x < = 2 * x - 14;

-69 * x < = 2 * x - 14;

-71 * x < = - 14;

x > = 14/71.