题目内容
(1)8ax＋12ay－10bx－15by;
(2)m2n2－a2b2＋n2a2－m2b2;
(3);
(4)25a2－4x2＋12xy－9y2;
(5)m3－m－8m2＋8;
(6)ax－ay＋3az－3bx＋3by－9bz;
(7)9－x2n＋2xnyn－y2n;
(8)(x－y)2－3x＋3y－40;
(9)(2x－y)2－14x＋7y＋12;
(10)(y2＋1)2＋3(y2＋1)－40．
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