999… 9 (1988 9) * 999 9 (1988 9) + 1999 9 (1988 9) =?

999… 9 (1988 9) * 999 9 (1988 9) + 1999 9 (1988 9) =?

=[1000... 000 (1988 0) - 1] * [1000... 000 (1988 0) - 1] + [2000... 000 (1988 0) - 1] = 1000... 000 (3976 0) - 2 * [1000... 000 (1988 0) - 1] + 1 + 2 * [1000... 000 (1988 0)] - 1 = 1000... 000 (3976 0)