设集合a=b={(x,y) x属于r,y属于r},点(x,y)在映射f:a到b的作用下对应的点是（x-y,x+y),则b中点（3,2）对应的a中点的坐标为

x��)�{�n���mO't$�&�VkT�Tj*T<�8�ɮ�"�J(�V�y�N���9+��X�tCK�U�ӎ I�g�<�;���Ovt?]���)@��g3ֿ��Q�[�S�]���cfғk�@Qc��{:�!@�ӹ�-h�c�MR�>�\��T������s�(�5G�D5�D�F��DhG�A����F:��������<[��n8��:�*�I���yv��K�