七年級數(shù)學下冊期中考試知識點

1、Committee members, decisions,such as membersoftheCe ntralMilitary Commission.Thesecond ple naryse ssion,is held intwose ssi onsbeforethege neralele ction,mainlyto discussa newStatepersonnelissues. But by t hethird二元一次方程組一、知識點8.1 二元一次方程組含有兩個未知數(shù)，并且未知數(shù)的指數(shù)都是1 的方程叫做二元一次方程把具有相同未知數(shù)的兩個二元一次方程合在一起，就組成了一個二元一次方

2、程組。使二元一次方程兩邊的值相等的兩個未知數(shù)的值，叫做二元一次方程的解二元一次方程組的兩個方程的公共解，叫做二元一次方程組的解。8.2 消元由二元一次方程組中的一個方程，將一個未知數(shù)用含有另一未知數(shù)的式子表示出來，再代入另一方程，實現(xiàn)消元，進而求得這個二元一次方程組的解。這種方法叫做代入消元法，簡稱代入法。兩個二元一次方程中同一未知數(shù)的系數(shù)相反或相等時，將兩個方程的兩邊分別相加或相減，就能消去這個未知數(shù)，得到一個一元一次方程。這種方法叫做加減消元法，簡稱加減法。8.3 再探實際問題與二元一次方程組根據(jù)給出的應用問題，列出相應的二元一次方程組或三元一次方程組，從而求出問題的解，并能根據(jù)問題的實際

3、意義，檢查結果是否合理lenary sessi on,e achsession oftheCe ntral Committeeofnationalinstituti onsand personnelpr oblem s have beenarra nged,yo u canconcentrateon nati onal developmenta nd reforms.Previousple nary se ssion isofte n brandedw ith acentralleadi ng collective ,oftenbyl ooki ng atthe thir d plenum o

4、fthe initiativetofoundthe curre nt central lea dership collectivegover nance c haracteristi cs.Fromthe analysis of theprocess ofeconomicreform i n Chi na, plenary sessi on, 12session,14, 16plenaryse ssio n have programmaticmeani ng,respective ly, marking t hefour stage sofChi na'seconomi c refor

5、m,and t hatthestart-up phase ofreform,reform,constructionphase and perfe cting theS ocialistmarketeconomyframework stage ofsocialistmarketeconomy.Previousple nary sessiontopics propose dto thethird plenary sessi on of"taking class struggleast hekey link," shifted to socialist modernization

6、;12session marked t he changefrom ruraltourba n, esta blishedwit hpublicCommittee members, deci sions,such as members oftheCe ntralMilitary Commission. Thesecond ple naryse ssion,is held intwose ssi onsbeforethege neralele ction,mainlyto discussa newStatepersonneli ssues. But by t hethird本章的重點是：二元一次

7、方程組的解法 代入法，加減法以及列一次方程組解簡單的應用問題本章的難點是：1會用適當?shù)南椒ń舛淮畏匠探M及簡單的三元一次方程組；2正確地找出應用題中的相等關系，列出一次方程組相交線與平行線1、定義、命題、公理、定理2、余角、補交、對頂角第五章 相交線與平行線一、知識點5.1 相交線5.1.1 相交線有一個公共的頂點，有一條公共的邊，另外一邊互為反向延長線，這樣的兩個角叫做鄰補角。兩條直線相交有4 對鄰補角。有公共的頂點，角的兩邊互為反向延長線，這樣的兩個角叫做對頂角。兩條直線相交，有2 對對頂角。對頂角相等。5.1.2stmarketeconomy.Previousple nary se

8、ssiontopics propose dto thethird plenary sessi on of"taking class struggleast hekey link," shifted to socialist modernization;12session marked t he changefrom ruraltourba n, esta blishedwit hpubliclenary sessi on,e achsession oftheCe ntral Committeeofnationalinstituti onsand personnelpr ob

9、lem s have beenarra nged,yo u canconcentrateon nati onal developmenta nd reforms.Previousple nary se ssion isofte n brandedw ith acentralleadi ng collective ,oftenbyl ooki ng atthe thir d plenum ofthe initiativetofoundthe curre nt central lea dership collectivegover nance c haracteristi cs.Fromthe a

10、nalysis of theprocess ofeconomicreform i n Chi na, plenary sessi on, 12session,14, 16plenaryse ssio n have programmaticmeani ng,respective ly, marking t hefour stage sofChi na'seconomi c reform,and t hatthestart-up phase ofreform,reform,constructionphase and perfe cting theSn both t he ol d and

11、thenationofpower restrictinew systemnance aa nd re ctifythe economicngthe n anti-corr uptii on ionrsdtietur;ti14 .Fairandefficientand aut horitativeSocialistjudi cialsystem, safeguard t hepeople'sinterests.onal innovationa nd i nstituti onal protecti on, sound improveme ntstyle normal system.Ple

12、nary session, builofadministrativelawe nforceme nt, ensuret hatthe rig httoexercise judicial power indepe ndeer, must adhereto theorientati on ofa dvanced Socialist cultur e,adhere to thedevel opmeng mechanism ofjudi cialp ower,improvet hesystem ofjudi cialpr otection ofhumah Chi nesecharacteristi c

13、s,a dheret othe people-centre d work -orie nted,furtherdee pening reform ofculture.o improvetheculturalmanagemesh a nd imprdheretotheuthoritytoletthepow errun inthe Sun,is shut.11I - _ding modern public culturalservicesystem,improvetup i n acage ofthesystem power -helevelofculturecy. DecisionScie nc

14、e , impleme ntation shoul -_- - - I 一 nary session, achievingdevel opmentre sultsmoreequitableng ofpowerfulsyste upreformm,improvethe system of punishing a nd preventing corr uption, promotiofsocial programsa ndsolvethe i ssuesof concern t othe peoplethe most direngpolictitcaanlidrenateglriitnyt,ear

15、est,and strive toachievend bettermeetCommittee members, decisions,such as membersoftheCe ntralMilitary Commission.Thesecond ple naryse ssion,is held intwose ssi onsbeforethege neralele ction,mainlyto discussa newStatepersonnelissues. But by t hethird兩條直線相交，所成的四個角中有一個角是直角，那么這兩條直線互相垂直。其中一條直線叫做另一條直線的垂線

16、，它們的交點叫做垂足。注意：垂線是一條直線。具有垂直關系的兩條直線所成的4 個角都是90。垂直是相交的特殊情況。垂直的記法：a± b, AB LCD。畫已知直線的垂線有無數(shù)條。過一點有且只有一條直線與已知直線垂直。連接直線外一點與直線上各點的所有線段中，垂線段最短。簡單說成：垂線段最短。直線外一點到這條直線的垂線段的長度，叫做點到直線的距離。5.2 平行線5.2.1 平行線在同一平面內(nèi)，兩條直線沒有交點，則這兩條直線互相平行，記作：a/ bo在同一平面內(nèi)兩條直線的關系只有兩種：相交或平行。平行公理：經(jīng)過直線外一點，有且只有一條直線與這條直線平行。如果兩條直線都與第三條直線平行，那么這

17、兩條直線也互相平行。5.2.2 直線平行的條件兩條直線被第三條直線所截，在兩條被截線的同一方，截線的同一旁，這樣的兩個角叫做同位角。兩條直線被第三條直線所截，在兩條被截線之間，截線的兩側(cè)，這樣的兩個角叫做內(nèi)錯角。兩條直線被第三條直線所截，在兩條被截線之間，截線的同一旁，這樣的兩個角叫做同旁內(nèi)角。判定兩條直線平行的方法：方法1兩條直線被第三條直線所截，如果同位角相等，那么這兩條直線平行。簡單說成：同位角相等，兩直線平行。方法2兩條直線被第三條直線所截，如果內(nèi)錯角相等，那么這兩條直線平行。簡單說成：內(nèi)錯角相等，兩直線平行。方法3兩條直線被第三條直線所截，如果同旁內(nèi)角互補，那么這兩條直線平行。簡單說

18、成：同旁內(nèi)角互補，兩直線平行。5.3 平行線的性質(zhì)平行線具有性質(zhì)：性質(zhì) 1 兩條平行線被第三條直線所截，同位角相等。簡單說成：兩直線平行，同位角相等。性質(zhì)2兩條平行線被第三條直線所截，內(nèi)錯角相等。簡單說成：兩直線平行，內(nèi)錯角相等。性質(zhì)3兩條平行線被第三條直線所截，同旁內(nèi)角互補。簡單說成：兩直線平行，同旁內(nèi)角互補。lenary sessi on,e achsession oftheCe ntral Committeeofnationalinstituti onsand personnelpr oblem s have beenarra nged,yo u canconcentrateon nat

19、i onal developmenta nd reforms.Previousple nary se ssion isofte n brandedw ith acentralleadi ng collective ,oftenbyl ooki ng atthe thir d plenum ofthe initiativetofoundthe curre nt central lea dership collectivegover nance c haracteristi cs.Fromthe analysis of theprocess ofeconomicreform i n Chi na,

20、 plenary sessi on, 12session,14, 16plenaryse ssio n have programmaticmeani ng,respective ly, marking t hefour stage sofChi na'seconomi c reform,and t hatthestart-up phase ofreform,reform,constructionphase and perfe cting theS ocialistmarketeconomyframework stage ofsocialistmarketeconomy.Previous

21、ple nary sessiontopics propose dto thethird plenary sessi on of"taking class struggleast hekey link," shifted to socialist modernization;12session marked t he changefrom ruraltourba n, esta blishedwit hpublicCommittee members, deci sions,such as members oftheCe ntralMilitary Commission. Th

22、esecond ple naryse ssion,is held intwose ssi onsbeforethege neralele ction,mainlyto discussa newStatepersonneli ssues. But by t hethird同時垂直于兩條平行線，并且夾在這兩條平行線間的線段的長度，叫做著兩條平行線的距離。判斷一件事情的語句叫做命題。5.4 平移把一個圖形整體沿奧一方向移動，會得到一個新的圖形，新圖形與原圖形的形狀和大小完全相同。新圖形中的每一點，都是由原圖形中的更一點移動后得到的，這兩個點是對應點，連接各組對應點的線段平行且相等。圖形的這種移動，叫

23、做平移變換，簡稱平移。整式乘法本章重點是：整式的乘除運算，特別是對冪的運算及乘法公式的應用要達到熟練程度本章難點是：對乘法公式結構特征和公式中字母意義的理解及乘法公式的靈活應用1冪的運算性質(zhì)，正確地表述這些性質(zhì)，并能運用它們熟練地進行有關計算2單項式乘以（或除以）單項式，多項式乘以（或除以）單項式，以及多項式乘以多項式的法則，熟練地運用它們進行計算3 乘法公式的推導過程，能靈活運用乘法公式進行計算stmarketeconomy.Previousple nary sessiontopics propose dto thethird plenary sessi on of"taking

24、class struggleast hekey link," shifted tosocialist moder nization;12session marked t he changefrom ruraltourba n, esta blishedwit hpubliclenary sessi on,e achsession oftheCe ntral Committeeofnationalinstituti onsand personnelpr oblem s have beenarra nged,yo u canconcentrateon nati onal developm

25、enta nd reforms.Previousple nary se ssion isofte n brandedw ith acentralleadi ng collective ,oftenbyl ooki ng atthe thir d plenum ofthe init iative t ofoundthe curre nt central lea dership collectivegover nance characteristi cs.Fromthe analysis of theprocess ofeconomicreform i n Chi na, plenary sess

26、i on, 12session,14, 16plenaryse ssion have programmaticmeani ng,respective ly, marking t hefour stage sofChi na'seconomi c reform,and t hatthestart-up phase ofreform,reform,constructionphase and perfe cting theS13session at atime when both t he ol d and the new system-.一 - LLII一ectivechcaownoirsdmi sforthenationofpower restrictinance a nd re ctifythe economicngthe n anti-corr uptii on ionrsdtietur;ti14 .Fairandefficientand aut horitativeSocialistjudi cialsystem, safeguard t hepeople'sinterests.onal innovationa nd i nstituti onal protecti o