(X^+Y^+1)*(X^+Y^-3)==12
(X^+Y^)^-2(X^+Y^)-3==12
(X^+Y^)^-2(X^+Y^)-15==0
(X^+Y^+3)*(X^+Y^-5)==o
1.X^+Y^=-3;
2.X^+Y^=5