About Number

the Interest thing about 10-base number
1 X 9 + 2 = 11
12 X 9 + 3 = 111
123 X 9 + 4 = 1111
1234 X 9 + 5 = 11111
12345 X 9 + 6 = 111111
123456 X 9 + 7 = 1111111
1234567 X 9 + 8 = 11111111
12345678 X 9 + 9 = 111111111

9 X 9 + 7 = 88
98 X 9 + 6 = 888
987 X 9 + 5 = 8888
9876 X 9 + 4 = 88888
98765 X 9 + 3 = 888888
987654 X 9 + 2 = 8888888
9876543 X 9 + 1 = 88888888
98765432 X 9 + 0 = 888888888

999999 X 2 = 11
999999 X 3 = 111
999999 X 4 = 1111
999999 X 5 = 11111
999999 X 6 = 111111
999999 X 7 = 1111111
999999 X 8 = 11111111
999999 X 9 = 111111111

what is the conclusion from these numbers???