)15()3)(2()1()1(392)23)(23(122222 xxxxxxkykxyxcbacba其中其中、求求是完全平方式，是完全平方式，、计算：、计算：填空：222abab 222aabb 22xyxy 222xxyy 222xxyy ，xy10，yx7已知.22的值求yx xyyxyx2:222解1027229(ab)2=a22abb2(ab)2=a22abb2，xy10，yx7已知.22的值求yx 227:yx解(ab)2=a22abb2(ab)2=a22abb249222yxyxxyyx249221024929，xx31已知.122的值求xx a2b2 =(ab)2 2ab221:xx解)1(2)1(2xxxx2)1(2xx2327，xx31已知.122的值求xx a2b2 =(ab)2 2ab911222xxxx223)1(:xx解91222xx7122xx.的值求xy，yx1已知，yx5221:2 yx解(ab)2=a22abb2(ab)2=a22abb21222yxyx1222yxxy152 xy512 xy2xy的最小值的最小值求求的最小值的最小值求求786220)(2222 yxyxxxyx
