Răspuns:
12 ; 24 ; 36 ; 48
Explicație pas cu pas:
___ ___
XY / YX = 4/7 <=>
(10x+y) / (10y+x) = 4/7 =>
7·(10x+y) = 4·(10y+x) =>
70x+7y = 40y+4x =>
70x-4x = 40y-7y =>
66x = 33y I: 33 =>
2x = y ; x,y ≠ 0 =>
x = 1 => y = 2
x = 2 => y = 4
x = 3 => y = 6
x = 4 => y = 8
Numerele xy sunt :
12 ; 24 ; 36 ; 48
#copaceibrainly