1分式的混合专题练习(1)2222223223xyyxyxyxyxyx(2)1111322aaaa.(3)21xx-x-1(4)3aa-263aaa+3a,(5)xyyyxxyxxy222(6)293261623xxx(7)xyyxyxyx2211(8)aaaaaa4)22(2.2(9)232224xxxxxx(10))1x3x1(1x1x2x22(11))252(23xxxx(12)(abba22+2)÷baba22(13)22321113xxxxxxx(14)xxxxxxxxx416)44122(2222(15)计算:xxxxxxxx4)44122(22,并求当3x时原式的值.