Răspuns :
Răspuns:
a+b=20
a-b=4 => a = 4+b
4+b+b=20
4+2b=20
2b=20-4
2b=16
b=16:2
b=8
a=4+8
a=12
Bafta! :D
Rezolvare: a-b=4=>a=b+4
a+b<20
a |____|__4__|
b |____|
b<(20-4):2
b<8 => b={0,1,2,3,4,5,6,7}
(a,b)=(4,0);(5,1);(6,2);(7,3);(8,4);(9,5);(10,6);(11,7)
a+b<20
a |____|__4__|
b |____|
b<(20-4):2
b<8 => b={0,1,2,3,4,5,6,7}
(a,b)=(4,0);(5,1);(6,2);(7,3);(8,4);(9,5);(10,6);(11,7)