Odpowiedź:
3/14 * (1 + 3 i 1/5 - 4 i 1/5 * 3/7 - 1) = 3/14 * (4 i 1/5 - 21/5 * 3/7 - 1) = 3/14 * (4 i 1/5 - 63/35 - 1) = 3/14 * (4 i 1/5 - 1 i 28/35 - 1) = 3/14 * (4 i 7/35 - 1 i 28/35 - 1) = 3/14 * ( 3 i 42/35 - 1 i 28/35 - 1) = 3/14 * ( 2 i 14/35 - 1) = 3/14 * 1 i 14/35 = 3/14 * 49/35 = 21/70 = 3/10