Răspuns:
ײ-y² = ( x + y) * (x - y)
15 = 5 * (x - y) => x - y = 3 => x = 3 + y
x + y = 5 => 3+y+y = 5
2*y = 2 => y = 1
x = 3 + 1 = 4
ײ+y² = 16 + 1 = 17
