Odpowiedź:
(4/5 + 1/15) * 15 = (12/15 + 1/15) * 15 = 13/15 * 15 = 13
3 i 5/6 - 2 * 1 i 1/4 = 3 i 5/6 - 2 * 5/4 = 3 i 5/6 - 10/4 = 3 i 5/6 - 2 i 2/4 =
3 i 10/12 - 2 i 6/12 = 1 i 4/12 = 1 i 1/3
