Question

Determinati numerele naturale ab,pentru care ab=54+ba.

Answer 1

ab = 54 + ba
10×a + b = 54 + 10×b + a
10×a- a= 54+10×b-b
9×a = 54 + 9×b
9×a - 9×b = 54
9(a-b) = 54 | :9
a -b = 6 => a = b+6
ab = 71,82 93

Verificare:
71 = 54 + 17
71 = 71
82 = 54 + 28
82 = 82
93 = 54 + 39
93 = 93

numerele sunt: 71,82,93