In today's modern notation of Roman numerals 549 is equivalent to DXLIX but the ancient Romans would have notated it quite differently.
549
549
549
Under the rules now governing the Roman numeral system that were set up in the Middle Ages long after the collapse of the Roman Empire the equivalent of 549 converted into Roman numerals is now considered to be DXLIX but the ancient Romans would have wrote it out simply as IDL which means 550-1 = 549
988 = CMLXXXVIII in Roman numerals
549
549
549
(vii)dxlix
Under the rules now governing the Roman numeral system that were set up in the Middle Ages long after the collapse of the Roman Empire the equivalent of 549 converted into Roman numerals is now considered to be DXLIX but the ancient Romans would have wrote it out simply as IDL which means 550-1 = 549
988 = CMLXXXVIII in Roman numerals
it means 1,150 in roman numerals
Those Roman Numerals mean 1991.
Not a valid sequence for Roman numerals
It does not mean anything because it is an invalid arrangement of Roman numerals
"D" in Roman Numerals equals 500.
Roman numerals don't have a 0 symbol and so it is an invalid arrangement of Roman numerals