ab - ba = 54
ab = 10 x a + b
ba = 10 x b + a
10 x a + b - 10 x b + a
ab - ba = 10 a + b - 10 b + a
ab - ba = 9 a - ( 10 b - b )
ab - ba = 9 a - 9 b
9 a - 9 b = 9 a - 9 b
9 a - 9 b = 54 ( 54 : 9 )
a - b = 6
a = 9 , 8 , 7
b = 3 , 2 , 1
ab = 93 , 82 , 71
ba = 39 , 28 , 17
Succes !!!
