Ответ:a · 9 = a + a + a + a + a + a + a + a + a.7 · k = k + k + k + k + k + k + k.(a + b) · 6 = (a + b) + (a + b) + (a + b) + (a + b) + (a + b) + (a + b).(x + z + 6) · 3 = (x + z + 6) + (x + z + 6) + (x + z + 6).