Задание

Укажите, верно или ошибочно выполнено преобразование выражений.

Верно

Неверно

23 + 9 = (20 + 3) + 9 = 20 + 12 = 32

23 + 9 = (20 + 1 + 2) + 9 = (31 + 9) + 2 = 40 + 2 = 42

23 + 9 = 23 + (7 + 2) = 23 + 7 = 30 + 2 = 32

23 + 9 = (21 + 2) + 9 = (21 + 9) + 2 = 30 + 2 = 32

23 + 9 = (30 – 7) + (7 + 2) = 30 – 7 + 7 – 2 = 28

23 + 9 = (30 – 7) + (7 + 2) = 30 – 7 + 7 + 2 = 32

23 + 9 = 23 + (10 – 1) = 33 – 1 = 32

23 · 9 = (20 + 3) · 9 = 20 · 9 + 3 · 9 = 180 + 27 = 207

23 · 9 = (20 + 3) · 9 = 20 · 9 + 3 · 9 = 18 + 27 = 45