Răspuns :
x= nr. de bacnote
10x = banii pe care ii are Ion
5x = Banii pe care ii are Dan
5x + 40= 10x |-5x
5x-5x+40=10x-5x
40=5x | :5
x=8
=> Dan are : 5x=5*8 = 40
=> Ion are : 10x = 10*8 = 80
Deci... Dan are 40 de lei , iar Ion are 80 de lei .
10x = banii pe care ii are Ion
5x = Banii pe care ii are Dan
5x + 40= 10x |-5x
5x-5x+40=10x-5x
40=5x | :5
x=8
=> Dan are : 5x=5*8 = 40
=> Ion are : 10x = 10*8 = 80
Deci... Dan are 40 de lei , iar Ion are 80 de lei .