摘要：合并同类项: ⑴3x2-1-2x-5+3x-x2 ⑵-0.8a2b-6ab-1.2a2b+5ab+a2b ⑶ ⑷6x2y+2xy-3x2y2-7x-5yx-4y2x2-6x2y (5)4x2y-8xy2+7-4x2y+12xy2-4, (6)a2-2ab+b2+2a2+2ab - b2．

网址：http://m.1010jiajiao.com/timu3_id_644879[举报]