1x 8+1=9
12x 8+2=98
123x 8+3=987
1234x8+4=9876
12345x 8+5=98765
123456x8+6=987654
1234567x8+7=9876543
12345678x8+8=98765432
123456789x8+9=987654321
1х9+2 =11
12х9+3=111
123х9+4=1111
1234х9+5=11111
12345х9+6=111111
123456х9+7=1111111
1234567х9+8=11111111
12345678х9+9=111111111
123456789х9+10=1111111111