1)X+Y=根号6， ① X-Y=根号5 ②①�0�5=x�0�5+2xy+y�0�5=6 ③②�0�5=x�0�5-2xy+y�0�5=5 ④③-④ 4xy=1 xy=1/42)A+B=6， 两边平方 A�0�5+2AB+B�0�5=36 AB=2， A�0�5+B�0�5=36-4 =32
(1)1/4(2)32
