Andrzej Bartz offered these “doubly true” alphametics in the May 2017 issue of Word Ways. If the letters in each equation encode digits, what mathematical facts do these expressions represent?

CCCLVI + CCCI + CCLI = CMVIII

ONE + THIRTYNINE + NINETYONE = THREE + NINE + THIRTY + EIGHTYNINE

TWO × TWO + TEN × FIVE = SIX × NINE