ab= nr natural
ab : ba = 2,08
(10a+b):(10b+a) = 208/100
(10a+b)/(10b+a) = 52/25
25(10a+b) = 52(10b+a)
250a+25b = 520b+52a
250a-52a = 520b - 25b
198a = 495b
495 = 5×3^×11
198 = 2×3^×11
198:11 = 18
495:11 = 45
18×a = 45×b
a = 5
b= 2
18×5 = 45×2
90 = 90
ab= 52
Verificare:
52:25 = 2,08
Numarul cautat este 52.