题目列表(包括答案和解析)
5、(2008浙江金华)化简a+b+(a-b)的最后结果是( )C
A、2a+2b B、2b C、2a D、0
4、(2008浙江金华)如果+3吨表示运入仓库的大米吨数,那么运出5吨大米表示为( )A
A、-5吨 B、+5吨 C、-3吨 D、+3吨
3、(2008湖南邵阳)等于( )D
A. B. C. D.
2.(08山东日照)下列计算结果正确的是( ) C
A. B.=
C. D.
1.(2008年四川省宜宾市)下列各式中,计算错误的是( )
A. 2a+3a=5a B. –x2·x= -x3 C. 2x-3x= -1 D.(-x3)2= x6
答案:C
76. 解: ………………………………………2分
= …………………………………………………………3分
= …………………………………………………………4分
=. ……………………………………………………………………5分
当时,原式=. …
75. 解:去分母,得
.·············································································· (3分)
整理,得.····················································································· (2分)
,.····························································································· (4分)
经检验,是增根,是原方程的根.··················································· (1分)
所以,原方程的根是.
74. 解:原式= ……………………………2分
= …………………………………………3分
=. ……………………………………………………………4分
当,时,
原式=.
73. 解:方程两边都乘以,得:
解得:
经检验:是原方程的根;
72. .解:设原计划每小时抢修的路线长为,根据题意,得
································································································ 5分
解之得
························································································································ 7分
检验:是原方程的解,且符合题的实际意义.
答:原计划每小时抢修的路线长为400m.···································································· 8分
湖北省互联网违法和不良信息举报平台 | 网上有害信息举报专区 | 电信诈骗举报专区 | 涉历史虚无主义有害信息举报专区 | 涉企侵权举报专区
违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com