先化简，再求值．（1）x2-4x+42x-4•(x+2)，其中x=5．（2）(x+1+4x-3)÷x-1x2-3x，其中x=3+1．-数学

更多内容推荐

• Last Christmas, The Washington Post published an essay _______ what kind of Christmas dolls are popu
• 已知=，求的值。-九年级数学
• 先化简，再求代数式2x+2x+2÷x2-1x+2的值，其中x=2+3tan30°．-数学
• Susan wanted to be independent of her parents. She tried ___________alone, but she didn’t like it an
• 用价值为100元的甲种涂料与价值为240元的乙种涂料配制成一种新型涂料，其每千克的售价比甲种涂料每千克的售价少3元，比乙种涂料每千克的售价多1元，求这种新型涂料每千克售价-八年级数学
• 2004年12月28日，我国第一条城际铁路-合宁铁路（合肥至南京）正式开工建设，建成后，合肥至南京的铁路运行里程将由目前的312km缩短至154km，设计时速是现行时速的2.5倍。旅客-八年级数学
• (2013·高考天津卷)In some languages,100 words make up half of all words ________ in daily conversations.A．
• 计算下列各题．（1）（2a-1b2）2•（-a2b3）•（3ab-2）3；（2）(xx-2-xx+2)÷4x2-x；（3）x2-1x2-2x+1+x2-2xx-2÷x；（4）a2+aa-1÷(a-aa
• Don't spend time beating on a wall, ________ to change it into a door.A．hopeB．hopingC．hopedD．to
• (2013·吉林一中二模)Programs，________to join the old and the young together, are growing in popularity all
• By the time I saw the job ________ in the newspaper，it was already too late.A．advertisedB．to be adve
• ________ her anger，Maria turned around and walked away from him.A．ControlledB．Being controlledC．To c
• Since the baby milk powder was found to be polluted, there has been universal doubt _____ other food
• The deer was lucky that it just missed ____ .A．catchingB．to be caughtC．being caughtD．to catch-高三英语
• _______our English teacher,our English has been greatly improved.A．Thanks toB．Thank forC．But forD．Ex
• all his courage, he invited Celine to get off the train with him．A．To gatherB．GatheredC．Gathering D．
• 列方程解应用题：某一工程进行招标时，接到了甲、乙两个工程队的投标书，施工1天需付甲工程队工程款1.5万元，付乙工程队工程款1.1万元，工程领导小组根据甲、乙两队的投标书-八年级数学
• (2013·高考北京卷)Volunteering gives you a chance________lives，including your own.A．changeB．changingC．chan
• ________ the words，the daughter understood what her mother was trying to tell her.A．To be heardB．To
• 先化简，再求值：a+1a-1-aa2-2a+1÷1a，其中a=3．-数学
• _______ by the rise of house price, people in big cities live under great pressure.A．To be affected
• This basket he sent me yesterday _______ many kinds of fruits, _______ apples and pears.A．contained;
• What difficulty will you have ____ people when you stay in a foreign country?A．understandB．understan
• In order not to be disturbed, he spent two hours ____ in his study.A．lockingB．to lockC．lockedD．being
• 对于公式1f=1f1+1f2（f2≠f），若已知f，f2，则f1=______．-数学
• 2 The bell ________ the end of the period rang, interrupting our heated discussion.A indicating B in
• We are invited to a party _________in our club next Friday. A．to be heldB．heldC．being heldD．holding
• (2013·高考四川卷)________which university to attend，the girl asked her teacher for advice.A．Not knowingB．
• (2013·高考安徽卷)________ in the early 20th century，the school keeps on inspiring children’s love of art.
• 已知a、b满足a-b+ab=0，且ab≠0，则1a-1b的值是（）A．1B．-1C．1abD．b-aab-数学
• 已知x-2y=0，求（）·的值。-九年级数学
• 已知1a-1b=12，则aba-b的值是（）A．12B．-12C．2D．-2-数学
• 某中学八年级﹙1﹚、﹙2﹚班计划组织部分同学义务植树180棵，由于同学们参与的积极性很高，实际参加植树活动的人数比原计划增加了50%，结果每人比原计划少栽了2棵树，问实际有多-八年级数学
• (2013·德州期末校际联考)________ an hour every day has made a considerable difference to my health.A．Having w
• 请从下列三个代数式中任选两个（一个作为分子，一个作为分母）构造一个分式，并化简该分式．（a2-1，a2-a，a2-2a+1）然后请你自选一个合理的数代入求值．-数学
• The boss took no notice of the suggestion given by the clerk that the new technology ____ the proble
• Heat wave sufferers said that they couldn’t get admitted into hospitals. They arrived at hospitals,
• (2013·高考湖南卷)________warm at night，I would fill the woodstove，then set my alarm clock for midnight so
• (2013·高考湖南卷)The sun began to rise in the sky，________the mountain in golden light.A．bathedB．bathingC
• 甲乙两班学生绿化校园，如果两班合作6天可以完工，如果单独工作，甲班比乙班少用5天。两班单独工作各要多少天完成？若设甲班单独工作要ｘ天完成，则根椐题意列方程是（）。-八年级数学
• 比邻而居的蜗牛神和蚂蚁王相约，第二天上午8时结伴出发，到相距16米的银杏树下参加探讨环境保护问题的微型动物首脑会议。蜗牛神想到“笨鸟先飞”的古训，于是给蚂蚁王留下一纸-八年级数学
• (2013·天津新华中学二次月考)________ several times，he still couldn't understand how to operate the machine
• ______ no bus, we had to take a taxi to go to the station.A．There wasB．There to beC．There had beenD
• ---- How did you know the surprising news? ---- I happened ____ the event then.A．to coverB．to be cov
• （1）先化简，再求值：(1+1x-1)÷xx2-1，其中：x=-2．（2）请先将下式先化简，再选择一个你喜欢的数代入求值：(1x-1-1x+1).x2-1x．-数学
• Bocai Middle School, which is reported just two years ago, is now reowned throughout Hunan Province.
• (2013·高考江苏卷)Lionel Messi ________ the record for the most goals in a calendar year，is considered the
• (2013·高考山东卷)I stopped the car ________ a short break as I was feeling tired.A．takeB．taking C．to take
• 计算：（1）a2a+1-1a+1；（2）(1+y-3y+3)÷-2yy2-9．-数学
• 联系实际编拟一道关于分式方程的应用题，要求表述完整，条件充分并写出解答过程。-八年级数学