MX$999 or MXP$999 are valid formats.
50000000
Mexico did not issue paper 1 Peso notes until 1920. Prior to that, 1 Peso was a coin.
The 1 Peso coins were introduced to replace the paper notes in 1972.
Either one point three million Peso, or one million three hundred thousand Peso. You should correct the peso in the above to the proper form for the multiple of peso - peso or pesos.
400 030 peso.
about 7000 US
Both "write in the paper" and "write on the paper" are correct phrases, but they have slightly different meanings. "Write in the paper" typically means to write within the boundaries of the paper, while "write on the paper" can imply writing on the surface of the paper.
one peso and ninety and nine tents = ₱190.90
A peso is about 10 cents. So in a pawn shop it would probably be a couple of pennies.
Many different Spanish speaking countries use or have used coins and paper money denominated as the "peso," which is the Spanish word for "pound." A coin or bill marked as "un peso" is a one peso coin or bill. The value of one peso depends on which country's currency is being assessed.
Which Peso? There are several currencies called the Peso, including the Chilean, Mexican and Cuban Pesos. Each has a different currency exchange rate, you need to write a new question telling which Peso you want the answer to.
No it is not valid anymore. They have new denominations: 1, 2, 5, 10, 20, 50 and 100 peso notes.