1)
a+7+a+23+a+25=70
3a+55=70
3a=70-55
3a-15
a=15:3
a=5
primul numar
7+5=12
al doilea numar
23+5=28
al treilea numar
25+5=30
PROBA
12+28+30=70
2)
x=70a+37
a=1;2;3;4;5;6;7;8;9........
x=70x1+37=70+37=107
x=70x2+37=140+37=177
x=70x3+37=210+37=247
...........................................
x=70x10+37=700+37=737
107:14=7 rest 9
177:14=12 rest 9
247:14=17 rest 9
737:14=52 rest 9
Indiferent de ce nr. natural ii dam lui a(inafara de 0),acel nr.inmultit cu 70 si impartit la 14 ne da restul 9