优课网
首页
数学
语文
英语
化学
物理
政治
历史
生物
首页
> 化简求值:,其中正数a满足a2+a﹣1=0.-九年级数学
化简求值:,其中正数a满足a2+a﹣1=0.-九年级数学
题目简介
化简求值:,其中正数a满足a2+a﹣1=0.-九年级数学
题目详情
化简求值:
,其中正数a满足a
2
+a﹣1=0.
题型:计算题
难度:中档
来源:广东省竞赛题
答案
解:原式=(
﹣
)
,
=
×
,
=
,
∵a2+a﹣1=0且a>0,
∴a2+a=1,a=
,
∴原式=
,
当a=
时,
原式=
=
=2.
上一篇 :
已知实数a,b,c满足abc=﹣1,a+b+c=4,,
下一篇 :
先化简再求值代数式:,已知:a=﹣.-九
搜索答案
更多内容推荐
先化简,再求值:,其中x=1+,y=1﹣.-九年级数学
The teacher asked the students __________ her _______ the word again.A.listen to; to readB.to hear;
When I got back home I saw a message pinned to the door, ______ “Sorry to miss you; will call later.
__________ the housing price, several measures have been adopted in the last two years.A.Lowering B.
计算:(1)(2)-八年级数学
化简:[+÷(+)2]·=()。-八年级数学
The 9th ASEM Summit, held in Laos in November 2012, was aimed at developing Asia-Europe cooperation
已知,则代数式=()-八年级数学
先化简,再求值:,其中,则它的值为()。-八年级数学
Chinese news reported today that a woman in Hongbai had been rescued after ____ in a tunnel for nine
I prefer ___for an outing by bike rather than __ at home on Sunday.A.go, stayB.to go, stayC.to go ,
The old man, ________ abroad for twenty years, is on the way back to his motherland.A.to workB.worki
计算:(1)=()(2)=()(3)=()(4)=()-八年级数学
________ the programme, they have to stay there for another two weeks.A Not completing B Not complet
________ of her happy childhood by the song, Grandma sang along with it in a soft voice. A.Reminded
________ himself with great strength, he raised himself.A.FilledB.To fillC.Being filledD.Filling-高三英
先化简,再求值:其中x=-3。-八年级数学
课堂上,朱老师出了这样一道题:“已知,求代数式(1+)÷的值。”那么代数式的值是()。-八年级数学
化简求值:当x=﹣2时,式子=()。-八年级数学
He risked __________ his job to see me off.A.LosingB.to riskC.being lostD.Lost-高二英语
I was ashamed _________ lied to my mother.A.to beB.of havingC.thatD.of being-高二英语
It is necessary ___ the magazines in time.A.to us to returnB.for us to returnC.to us returningD.that
He seems __________ what he is looking for.A.to have forgotten B.to forgetC.forgettingD.being forgot
The examination results _____in the speech of our headmaster delighted all of us.A.refer toB.referri
John rushed out in a hurry, ____ the door ____.A.leaving ; unlockingB.left; unlockedC.leaving; unloc
化简:[+÷(+)2]×=()-八年级数学
At the beginning of class, the noise of desks _______ could be heard outside the classroom.[ ]A. ope
已知的值为()。-八年级数学
先化简后求值,其中a=﹣2,则(1+)(a2﹣1)=()。-八年级数学
化简:=()。-八年级数学
化简求值:当时,÷=()-八年级数学
化简求值:当x=﹣2时,式子=()-八年级数学
“XiJinping's report, ” a smile on his face, he continued, “_____ to several hot topics, discuss
计算的正确结果是[]A.B.1C.D.-1-八年级数学
—Are all the titles of the articles in the contents?—Yes, all.A.listed; includedB.listing; includesC
“We can’t go out in this weather,”said Bob,________out of the window.A.lookingB.to lookC.lookedD.hav
School kids take part in parades on campus on Halloween, __________ in colorful costumes, after whic
(1)计算:++(﹣1)0﹣2sin45°=()(2)化简:=()-八年级数学
–Do you know what Mike does all day?–I know he spends at least as much time watching TV as he _____
如果2,那么的值为[]A.B.1C.D.2-八年级数学
已知,则等于[]A.B.1C.D.0-七年级数学
先化简,再求值:,其中,则它的值为().-八年级数学
化简:=()。-九年级数学
--- I regret ________ you that John has been fired. --- I can hardly believe my ears. He is such a f
What he wants is _______ his mother as quickly as he can; and what he must do is ____ to the hospita
___________ that he was in great danger, Eric walked deeper into the forest.A.Not realizedB.Not to r
—What do you think made the girl so depressed? —_____ with her boyfriend.A.As she broke up B.Break u
Please excuse me for _____ in without ______.A.coming, askingB.coming, being askedC.to come, askingD
Today we have chat rooms, text messaging, emailing… but we seem ________the art of communicating fac
When the farmers were asked to leave their hometown, they said they would rather______ than ______ t
返回顶部
题目简介
化简求值:,其中正数a满足a2+a﹣1=0.-九年级数学
题目详情
答案
=
=
∵a2+a﹣1=0且a>0,
∴a2+a=1,a=
∴原式=
当a=
原式=