The units' digit of a two-digit number is 7 more than the tens' digit. if 26 is added to the number, the result obtained is five times the sum of the digits. find the number.
xy - the number A) y -x = 7 B) (10x + y + 26) = 5 (x + y) B) 10x +y + 26 = 5x +5y B) 5x -4y = -26 multiplying equation A) by 4 A) 4y -4x = 28 Adding this to equation B B) 5x -4y = -26 x = 2 y = 9