初中数学整式加减培优(含解析)

经典word整理文档，仅参考，双击此处可删除页眉页脚。本资料属于网络整理，如有侵权，请联系删除，谢谢！初中数学整式加减培优考试要求：能根据特定的问题所提供的资料,合理会求代数式的值,能根据代数式的值或特征,推断这些代数式反映的规律选用知识和方法,通过代数式的适当变形求代数式的值.能用整式的加减运算对多项式进行变型,进一步解决有关问题.会进行简单的整式加减运算重难点：课前预习：??????????例题精讲：模块一整式相关概念】xy4xy2xy1按223x2星xy4xy2xy1按2xyxy4xy1223x3224xy22xyxy4xy14xy3222】xx5x3x1ab4332x2星axxbx3xa103033bab322ab】5xyn3y2xym2n2m2222星2m4且n30m2n3m2n3m2n1；22当m2，n3m2n22(m2)xm21y3xym232星【解析】由题意得m213202当2(m2)xy3xymmmm2123.2】设nxy4mnmn3星4mnm≥nmnmn≥mnmnmn】x2xy3xy4xy...x10982733星210，77xy和11y104610【答案】10】94x4xyy222星294x4xyy．2294x4xyy2【巩固】将多项式12ab2ab222星212ab2abab2．2【答案】12ab2abab2】1与3xy则(ab)xya1ab320122星2,11得2,0∴2abaababA模块二整式加减23】12x3x)x2x21．B．3．6．923星2x12∴2x3x36∴2x3x3Bx2223B】x2x3x7x8x13x24324星x7x8x13x1532x32x7x32x8x13x154322912x4xx14x8x13x152x4x242x2x241822222【巩固】若a2a10则2a4a=.223星281027()x2xx3x268683星【解析】∵10∴x2x1∴x2xx32x27x3x2x27xx2xx27x2x76C】当1m3145=.a3b24星1210∴ab10∴821∴433a3ba3b111∴4555a3b2225】当2时,117,1时,125x3x34星1∴49∴12512ab553ab3】化简：x0.5x0.2xx0.3xn1nn1nn12星(10.2)x(0.510.3)x0.8x0.2xn1nn1n0.8x0.2xnn15(xy)(yx)2(yx)3(xy)(xy)3222星【解析】原式5(xy)(xy)2(xy)3(xy)(xy)(xy)3(xy)2(xy)223325(xy)(xy)2(xy)3(xy)(xy)(xy)3(xy)2(xy)22332】化简：2(ab)ba)6(ba)ab)222星2(ab)(ab)6(ab)ab)8(ab)10(ab)2222(ab)(ab)6(ab)ab)8(ab)10(ab)222(ab)3(ab)2(ba)2222星(ab)3(ab)2(ab)4(ab)22224(ab)2】若A9abb1，B7abb2⑴2⑴3BAAB3232332星⑴2AB2(9abb1)(7abb2)ab7abb32323332233⑴3BA3(7abb2)(9abb1)21ab9abb723332323323⑴ab7abb⑴ab9abb73223323323【巩固】求ab6ab与6a7abb2333222星ab6ab)(6a7abb)4abb233323234abb32】若A2x5xy3y，B2x3xy4y2A3BC0C22222星【解析】由ABC230得：C2A3B2(2x5xy3y)3(2x3xy4y)2x19xy6y2222222x19xy6y22】化简：4xy3xyxyxy[2xy4xy(xy2xy)]}222222223星【解析】(法：(由内向外逐层去括号)原式4xy3xy[3xyxy(2xy4xyxy2xy)]222222224xy3xy(3xyxy3xy)4xy3xy6xyxy3xy9xy22222222222法)4xy3xy3xyxy[2xy4xy(xy2xy)]222222223xy6xy2xy4xy(xy2xy)5xy10xyxy2xy3xy9xy2222222222223xy9xy22x2xy2y23223星x2xy2y2A3AA.A22所以这三个多项式的和为：AAA[AA2A3A2A36A66(x2xy2y)66x12xy12y622226x12xy12y622】有这样一道题：“A2abc，Babc，Cc2ab，222222222当a1b2c3ABCb2，c33星ABC(2abc)ab2c)(c2ab)ab2，2222222222c3.ABC(2abc)ab2c)(c2ab)a2222222222】已知代数式3x220x243216x23424星当2320x43cx2222234a3b2cd216x2a2b2c2d343222a2c33642即2234a2c23的值为18x4cx28bc1若3，4，7cbbcaab(2a2).abca2bca2273星、、abc7a2bca2bcabc(a2)2bcab3，4，2bcaba2ab17c127127994星acabc换accba为100a10bc100c10ba99ac99整除99999297495495】55,,,41)D4星mabcde则m11eadb是B课堂检测：13、、⑴5a32b20⑴是7abc2x2aybcbaab2abcaca3b4a2cabc22223星5a32b2030，203，2.2abab⑴1为72312c71，x2(3)2cc3ababacabacacab2222222当a3，b2，c1时，原式1332321337522233522xxx22x2xx2星6x2628x33当x128b6a2)33星【解析】∵2338238∴ab2310∴abb6a232ab230232,,abcca-101b若P3ac2abbcc,Q3bc4acb2b5a2QP4星101cab∴P3ac2abbcc3ac2abbcc5abc∴Q3bc4acb2b5a3bc4acb2b5a6ab2c∴Q2P6ab2c25abc4ab48ababab(xPm)|yn04是同类项，且，已知：22n与32mA3x3y32xy1，Bx2yxy21，c2x3y3x2y22xy1，当2A6BC1P3星9610课后作业：1m1am3b与ab4nm与nnm11.3441星m31114，2，，m与nmmn1n24n1441219m4，