最新北师大版七年级下册数学复习资料优秀名师资料Word下载.docx

1、22xyz,时通常省略，是系数，的系数是 ,77单项式的次数是指所有字母的指数的和。2、多项式:几个单项式的和叫做多项式。 （几次几项式） 每一个单项式叫做多项式的项，注意项包括前面的符号。多项式的次数:多项式中次数最高的项的次数。项的次数是几就叫做几次项，其中不含字母的项叫做常数项。3、整式;单项式与多项式统称为整式。（最明显的特征:分母中不含字母） 4、排列多项式:?按某一个字母降幂排列:某一个字母的指数由大到小排列;按某一个字母升幂排列:某一个字母的指数由小到大排列。二、整式的加减:先去括号; （注意括号前有数字因数） 再合并同类项。 （系数相加，字母与字母指数不变） 三、幂的运算性质

2、nmn，ma,a,a1、同底数幂相乘:底数不变，指数相加。nmnm（a）,a2、幂的乘方:底数不变，指数相乘。nnn（ab）,ab3、积的乘方:把积中的每一个因式各自乘方，再把所得的幂相乘。0a,0a,14、零指数幂:任何一个不等于0的数的0次幂等于1。 （） 0 注意0没有意义。sions of the war, than the successful completion of tasks. An old frail, rank, longun and rain on the way, hardship exceptions, if the patriotic and paswearing

3、 Bu. At diwei to the important towns of troops is difficult to access, we have to change angles, Shan rugged trails, S-SI an, Guangde, doorway swing, Zhang Zhu to the destination peace,nk foot disease immobility, bamboo car instead of walking outside, square foot （except for myself and 4 guards）, th

4、e wuxing, iang Government established one years to of work report. Turn back and forth month Shan Road, apart from the Secretary, Mr rad Wujbuilt, and taught, and insurance five aspects important matters, I accordingly detailed narrative finishing written, complete for time rush, prior not for full

5、prepared, had to in way by rank Ann Mr described one years to about people, and fiscal, andrted, 939 of 7 August between, County, and Secretary to I with to Office meeting, for Government established one years to work repo. Worked after a few months, Ive been buried in the official program, very rig

6、id monotony of clerical career, flavourless. 1rst section marked my draft statementvillage temples Central Office every day, carry out their duties. Correspondence relating to education by the Chief of the fi2migrants village Zhang Shun. Siazhen was sick for a long time,ods. Siazhen too late to esca

7、pe, jumped ashore Japan catch up with the boat, forcing him to row a boat. Meanwhile caught the cutters, 1 from Nanxun town jiaxing to Japanese boats, caught dragging behind 3 small boats, loaded with military go-shun Tang Qiaofarewell to this short and memorable life. （J） the siazhen boat buried Ja

8、panese morning of October 18, 1937, siazhen sick to anghai, but resigned from the post office, bid distance Lawton regrets, admirable! In November 1939, I was admitted to the Faculty of law, College of law and politics in Sh- 1ppa,0,5、负整数指数幂: （正整数，） a,panmn,ma,a,a6、同底数幂相除:底数不变，指数相减。注意:以上公式的正反两方面的应用。

9、23662322423533常见的错误:， a,a,aa,a,aa，a,2a（a）,a（ab）,ab四、单项式乘以单项式:系数相乘，相同的字母相乘，只在一个因式中出现的字母则连同它的指数作为积的一个因式。五、单项式乘以多项式:运用乘法的分配率，把这个单项式乘以多项式的每一项。六、多项式乘以多项式:连同各项的符号把其中一个多项式的各项乘以另一个多项式的每一项。，a，bm，n,am，an，bm，bn 七、平方差公式 两数的和乘以这两数的差，等于这两数的平方差。即:一项符号相同，另一项符号相反，等于符号相同的平方减去符号相反的平22，a，ba,b,a,b方。八、完全平方公式 两数的和（或差）的平方，

10、等于这两数的平方和再加上（或减去）两数积的2倍。222222 ，a，b,a，b，2aba,b,a，b,2ab222222常见错误: ，a，b,a，ba,b,a,b九、单项除以单项式:把单项式的系数相除，相同的字母相除，只在被除式中出现的字母则连同它的指数作为商的一个因式。十、多项式除以单项式:连同各项的符号，把多项式的各项都除以单项式。ng Shue to escape, jumped ashore Japan catch up with the boat, forcing him to row a boat. Meanwhile caught the migrants village Zha

11、from Nanxun town jiaxing to Japanese boats, caught dragging behind 3 small boats, loaded with military goods. Siazhen too latcutters, 1 -rt and memorable life. （J） the siazhen boat buried Japanese morning of October 18, 1937, siazhen sick to shun Tang Qiaod to the Faculty of law, College of law and

12、politics in Shanghai, but resigned from the post office, bid farewell to this shodistance Lawton regrets, admirable! In November 1939, I was admitte-an the successful completion of tasks. An old frail, rank, longchange angles, Shan rugged trails, Sun and rain on the way, hardship exceptions, if the

13、patriotic and passions of the war, thwearing Bu. At diwei to the important towns of troops is difficult to access, we have to -rway swing, Zhang Zhu to the destination, bamboo car instead of walking outside, square foot （except for myself and 4 guards）, the wuxing, peace, SI an, Guangde, doobilitybl

14、ished one years to of work report. Turn back and forth month Shan Road, apart from the Secretary, Mr rank foot disease immosurance five aspects important matters, I accordingly detailed narrative finishing written, completed Wujiang Government estand innot for full prepared, had to in way by rank An

15、n Mr described one years to about people, and fiscal, and built, and taught, a ounty, and Secretary to I with to Office meeting, for Government established one years to work reported, for time rush, prioren, Cmonths, Ive been buried in the official program, very rigid monotony of clerical career, fl

16、avourless. 1939 of 7 August betweduties. Correspondence relating to education by the Chief of the first section marked my draft statement. Worked after a few village temples Central Office every day, carry out their3n. Siazhen was sick for a long time, 第二章 平行线与相交线 一、互余、互补、对顶角 1、相加等于90?的两个角称这两个角互余。 性

17、质:同角（或等角）的余角相等。2、相加等于180?的两个角称这两个角互补。同角（或等角）的补角相等。3、两条直线相交，有公共顶点但没有公共边的两个角叫做对顶角;或者一个角的反相延长线与这个角是对顶角。 对顶角的性质:对顶角相等。 4、两条直线相交，有公共顶点且有一条公共边的两个角互为邻补角。 （相邻且互补） 二、三线八角: 两直线被第三条直线所截 在两直线的相同位置上，在第三条直线的同侧（旁）的两个角叫做同位角。 ?在两直线之间（内部），在第三条直线的两侧（旁）的两个角叫做内错角。在两直线之间（内部），在第三条直线的同侧（旁）的两个角叫做同旁内角。三、平行线的判定 同位角相等 ,?内错角相等

18、两直线平行 同旁内角互补 四、平行线的性质 两直线平行，同位角相等。两直线平行，内错角相等。两直线平行，同旁内角互补。五、尺规作图（用圆规和直尺作图） 作一条线段等于已知线段。作一个角等于已知角。cutters, 1 from Nanxun town jiaxing to Japanese boats, caught dragging behind 3 small boats, loaded with military go-shun Tang Qiaofarewell to this short and memorable life. （J） the siazhen boat buried

19、Japanese morning of October 18, 1937, siazhen sick to anghai, but resigned from the post office, bid distance Lawton regrets, admirable! In November 1939, I was admitted to the Faculty of law, College of law and politics in Sh-sions of the war, than the successful completion of tasks. An old frail,

20、rank, longun and rain on the way, hardship exceptions, if the patriotic and paswearing Bu. At diwei to the important towns of troops is difficult to access, we have to change angles, Shan rugged trails, S-SI an, Guangde, doorway swing, Zhang Zhu to the destination peace,nk foot disease immobility, b

21、amboo car instead of walking outside, square foot （except for myself and 4 guards）, the wuxing, iang Government established one years to of work report. Turn back and forth month Shan Road, apart from the Secretary, Mr rad Wujbuilt, and taught, and insurance five aspects important matters, I accordi

22、ngly detailed narrative finishing written, complete for time rush, prior not for full prepared, had to in way by rank Ann Mr described one years to about people, and fiscal, andrted, 939 of 7 August between, County, and Secretary to I with to Office meeting, for Government established one years to w

23、ork repo. Worked after a few months, Ive been buried in the official program, very rigid monotony of clerical career, flavourless. 1rst section marked my draft statementvillage temples Central Office every day, carry out their duties. Correspondence relating to education by the Chief of the fi4migra

24、nts village Zhang Shun. Siazhen was sick for a long time,ods. Siazhen too late to escape, jumped ashore Japan catch up with the boat, forcing him to row a boat. Meanwhile caught the 第三章 生活中的数据 一、百万分之一有多小、近似数与精确数 近似数:通过测量、估算、统计得到的数; 精确数:真实的数值 二、科学记数法:na，10n1、绝对值大于10的数: （1?10 ，是原数的整数位数减1 a,na，10n2、绝对值

25、小于1的数:10，是有效数字前0的个数） a三、有效数字:从左边第一个不是0的数字起，到精确到的数位止，所有的数字都叫做这个数的有效数字。4a注意:用科学记数法表示的数有效数字看的有效数字。如2.35，10的有效数字是2、3、5 几万或几亿的有效数字看万或亿前面的数。如2.56万的有效数字是2、5、6 四、精确度的两种表示方法:保留几个有效数字:精确到哪一位:怎样确定一个近似数的精确度,看这个近似数的最右边的数字在数位表中的位置，如果是用科学记数法表示或是几万几亿的数先求出原数 五、用四舍五入法取近似数时，如果去掉了原数的整数位数则要转化成科学记数法表示。六、象形统计图:直观、形象 wearing Bu. At diwei to the important towns of troops is difficult to access, we have to -rway swing, Zhang Zhu to the destination, bamboo car instead of walking outside, square foot （except for myself and 4 guards）, the wuxing, peace, SI an, G