The ten's digit of a two-digit number is 3 more than the units' digit The number is 8 more than six times the sum of the digits Find the number?

Answer 1

Let x be the unknown number and let y be the ten's digit,

then x = 10y + y - 3 = 11y - 3,

and x = 8 + 6(y + y - 3) = 8 + 6(2y - 3) = 8 + 12y - 18 = 12y -10,

therefore 12y - 10 = 11y - 3.

Subtracting 11y and adding 10 to each side, y = 7.

Since the ten's digit is 7, the unit's digit must be 4, and the number is 74.