you are the number 48
56. Tens digit is greater than 4 and less than 6 so it can only be 5, so the number is 5X. It is one less than the number whose digits sum to 12, so its digits sum to 12-1 = 11 → 5 + X = 11 → X = 11 - 5 = 6 → the number is 56.
6
12 and 26
They are 7 and 5.
you are the number 48
56. Tens digit is greater than 4 and less than 6 so it can only be 5, so the number is 5X. It is one less than the number whose digits sum to 12, so its digits sum to 12-1 = 11 → 5 + X = 11 → X = 11 - 5 = 6 → the number is 56.
6
44 and 32
12 and 26
They are 7 and 5.
390 480 570
21 > 3x + 12 < n +5
12
57
x+8=20+12
I assume you mean the sum of the digets equal 12. In that case your problem has only one solution and that is 39. No other number satisfies those criteria