已知x2+y2=26,xy=3,求(x+y)2和(x-y)2的值.
∵x2+y2=26,xy=3,
∴①x2+y2+2xy=26+6,
(x+y)2=32;
②∵x2+y2-2xy=26-6,
∴(x-y)2=20.
故答案为:(x+y)2=32,(x-y)2=20.
已知x2+y2=26,xy=3,求(x+y)2和(x-y)2的值.
∵x2+y2=26,xy=3,
∴①x2+y2+2xy=26+6,
(x+y)2=32;
②∵x2+y2-2xy=26-6,
∴(x-y)2=20.
故答案为:(x+y)2=32,(x-y)2=20.