Найдите все двухзначные числа если ab+ba=121

a ≠ 0, b ≠ 0,

a, b = {1,2,3,4,5,6,7,8,9, },

ab + ba = 121,

ab + ba = 10 a + b + 10b + a = 11a + 11b = 11 (a + b),

11 (a + b) = 121,

a + b = 11,

b = 11 - a,

a ≠ 1, b ≠ 1,

a = 2, b = 9,

a = 3, b = 8,

a = 4, b = 7,

a = 5, b = 6,

a = 6, b = 5,

a = 7, b = 4,

a = 8, b = 3,

a = 9, b = 2,

Ответ: 29, 38, 47, 56, 65, 74, 83, 92.