Ответ:\(578 = 500 + 50 + 20 + 8\) → DLXXVIII.\(764 = 500 + 200 + 60 + 4\) → DCCLXIV.\(2997 = 2000 + 900 + 90 + 7\) → MMCMXCVII.Ответ: 578 — DLXXVIII; 764 — DCCLXIV; 2997 — MMCMXCVII.