Question

Помогите решить плез.

Answer 1

№1

1) 7 ≤ a ≤ 10|·3; 21 ≤ 3a ≤ 30. 2) 7 ≤ a ≤ 10|-3; 4 ≤ a - 3 ≤ 7.

3) 7 ≤ a ≤ 10|·(-3); -30 ≤ -3a ≤ -21.  4) -30 ≤ -3a ≤ -21|+6;  -24 ≤ 6 -3a ≤ -15.

4) 7 ≤ a ≤ 10|·2; 14 ≤ 2a ≤ 20|+3; 17 ≤ 2a+3 ≤ 23.

№2

P = 3a, 7 ≤ a ≤ 8|·3; 21 ≤ 3a ≤ 24; 21 ≤ P ≤ 24.

Answer 2

Точно так?

Answer 3

да