七年级数学解二元一次方程组与不等式练习题范文.doc

- 5 -知识改变命运，学习成就未来解二元一次方程组专题训练一、基础过关1用加、减法解方程组，若先求x的值，应先将两个方程组相_；若先求y的值，应先将两个方程组相_2解方程组用加减法消去y，需要（ ） A2- B3-2 C2+ D3+23已知两数之和是36，两数之差是12，则这两数之积是（ ） A266 B288 C-288 D-1244已知x、y满足方程组，则x：y的值是（ ） A11：9 B12：7 C11：8 D-11：85已知x、y互为相反数，且（x+y+4）（x-y）=4，则x、y的值分别为（ ） A B C D6已知a+2b=3-m且2a+b=-m+4，则a-b的值为（ ） A1 B-1 C0 Dm-17若x5m+2n+2y3与-x6y3m-2n-1的和是单项式，则m=_，n=_8用加减法解下列方程组：（1） （2）（3） （4）二、综合创新9已知关于x、y的方程组的解满足x+y=-10，求代数m2-2m+1的值10（1）今有牛三头、羊二只共1900元，牛一头、羊五只共850元，问每头牛和每只羊各多少元？ （2）将若干只鸡放入若干个鸡笼中，若每个鸡笼放4只，则有一只鸡无笼可放；若每个鸡笼放5只，则有一个笼无鸡可放，那么有鸡多少只？有鸡笼多少个？11在解方程组时，哥哥正确地解得，弟弟因把c写错而解得，求a+b+c的值12（1）解方程组 （2）已知等式（2A-7B）x+（3A-8B）=8x+10对一切实数x都成立，求A、B的值三、培优训练13（探究题）解方程组自我小结：成功之处：不足之处：一元一次不等式专题训练一、填空题：1 用不等式表示： a大于0_； 是负数_； 5与x的和比x的3倍小_.2不等式 的解集是_.3用不等号填空：若.4当x_时，代数代的值是正数.5不等式组 的解集是_.6不等式的正整数解是_.7的最小值是a，的最大值是b，则8生产某种产品，原需a小时，现在由于提高了工效，可以节约时间8%至15%，若现在所需要的时间为b小时，则_ b _.9编出解集为的一元一次不等式为_.10若不等式组 的解集是空集，则a、b的大小关系是_.二、选择题：11下列不等式中，是一元一次不等式的是（ ） A2x10 B-12 C3x-2y-1 Dy2+3512不等式的解集是（ ）Ax Bx Cx Dx 13一元一次不等式组 的解集是 （ ） A-2x3 B-3x2 Cx-3 Dx214如图1，在数轴上所表示的是哪一个不等式的解集（ ） A B Cx+1-1 D-2x415下列两个不等式是同解不等式的是（ ） A与 B与C与 D 与16解下列不等式组，结果正确的是( ) A不等式组 的解集是x3 B不等式组 的解集是-3x-2 C不等式组 的解集是x-1 D不等式组 的解集是-4x217若 ，则a只能是（ ） Aa-1 Ba0 Ca-1 Da018关于x的方程的解是非负数，那么a满足的条件是( ) Aa3 Ba3 Ca3 Da3三、解一元一次不等式（或不等式组），并把它们的解集在数轴上表示出来.196x7x-2 20四、解答题：21 x为何值时，代数式 的值比代数式 的值大.22已知关于x、y的方程组.（1）求这个方程组的解；（2）当m取何值时，这个方程组的解中，x大于1，y不小于1.23已知方程组 的解为负数，求k的取值范围24某种植物适宜生长在温度为1820的山区，已知山区海拔每升高100米，气温下降0。5，现在测出山脚下的平均气温为22，问该植物种在山的哪一部分为宜？（假设山脚海拔为0米）自我小结：成功之处：不足之处：作为一名测量人员，xx认真履行岗位职责，紧密配合施工，制定切实可行的的测量放线方案。保罗回忆自己年少时癿经历，丌断怃耂生命、医疗、道德不哲学乊间癿兰系，丌仅为从医考提供了新规觇，使他们对自己癿职业呾使命有更为深入癿怃耂，耄丏为读考引路，觑人们更勇敢、沉着地看待生命、死亜不未来。situation, causing the livelihood of 100 tailings project management project and South Mining Technology in two engineering work lag. Corrective measures: (LED Leadership: Luo Mingjun, rectification time: before September 25th, insist for a long time) 1, strictly abide by the partys political discipline. Strictly abide by the constitution, the principle of Party organization and party political life standards, do not spread against the partys theory and policy advice, not contrary to published The central and provincial Party committee decided to talk, not to divulge the secrets of the party and the state, do not make no illegal organization and participate in various activities, political, spread rumors and false information, not to publish lossy unity of speech, do not damage the unity of things, and never allow individuals above the organization. 2, adhere to the scientific and democratic decision-making the decision to make decisions. Correctly handle to ensure that government decrees and based on the actual creative work, giving full play to subjective initiative, put an end to implement the conference meeting, to document the implementation of documents and so on. To improve the scientific and democratic decision-making mechanism, improve and implement the decision to solicit opinions, experts, public hearings and other health system. All major decisions before the risk assessment mechanism and legitimacy review mechanism. Adhere to the interests of the masses and the intention reflected in the policy making process and carry out the work, not acting on their behalf, across the board and coercion. (two) the existence of negative communication or unwilling to communication problems due to maintenance party team unity. The team members of the division of responsibilities, temperament, interestsDifferences in demand, often leads to different views, different opinions. Individual members of organization and coordination ability, team spirit is not good, work style is not real, simple working methods, lack of knowledge of the wisdom of the people, forgiveness and art for the people, can not deal with different opinions, there are self sweep the snow in front of the door, all kinds of responsibility fields. Some members of the team division of work coordination, lack of coordination, as extreme liberalization, did not form a work force. In addition, individual cadres lack of leadership training, love command communication, negative communication, talk in the work did not take the initiative to talk not correct The science team differences, resolve conflicts. Corrective measures: (LED Leadership: Luo Mingjun, rectification time: before September 25th, insist for a long time) 1