Răspuns :
D+T= 648
T=D+20
D+D+20= 648
2*D= 648-20
2*D= 628
D= 314
T= 314+20= 334
Verificare: 314+334= 648
T=D+20
D+D+20= 648
2*D= 648-20
2*D= 628
D= 314
T= 314+20= 334
Verificare: 314+334= 648