6. Найди значения выражений b + 20, 14 + b, 80-b и b -9 при b = 70, b=23 и b = 11.

1. Если b = 70, то:

   $$b + 20 = 70 + 20 = 90$$

   $$14 + b = 14 + 70 = 84$$

   $$80 - b = 80 - 70 = 10$$

   $$b - 9 = 70 - 9 = 61$$

2. Если b = 23, то:

   $$b + 20 = 23 + 20 = 43$$

   $$14 + b = 14 + 23 = 37$$

   $$80 - b = 80 - 23 = 57$$

   $$b - 9 = 23 - 9 = 14$$

3. Если b = 11, то:

   $$b + 20 = 11 + 20 = 31$$

   $$14 + b = 14 + 11 = 25$$

   $$80 - b = 80 - 11 = 69$$

   $$b - 9 = 11 - 9 = 2$$

Ответ: При b = 70: b + 20 = 90, 14 + b = 84, 80 - b = 10, b - 9 = 61; при b = 23: b + 20 = 43, 14 + b = 37, 80 - b = 57, b - 9 = 14; при b = 11: b + 20 = 31, 14 + b = 25, 80 - b = 69, b - 9 = 2