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已知x1、x2是方程x²-3x+1=0的两根则x1²+x2²=?1/x1+1/x2=? 已知方程X²-3X-1=0的两根为X1和X2,则(X1-3)(X2-3)的值是? 已知方程x²+3x-1=0的两根为X1,X2,求做一个方程,使它的两根是x2／x1,x1／x2 1 已知X1,X2是方程X²+3X+1=0的两实根,则X1²+8X2+20=? 14．已知x1、x2为方程x²＋3x＋1＝0的两实根,则x1²＋8x2＋20＝__________． Quota exceeded mailbox for user is 请高手写一篇paragraph,读完"Morning has broken"的感受,250-300英文单字左右.（参考诗歌在补充问题里面）"Morning Has Broken"by Eleanor Farjeon Morning has broken,like the first morningBlackbird has spoken,like the first birdP 为什么说“玉者,国之重器也”?有什么出处或典故? 玉者国之重器 怎么确定房屋方向和方位 英语Can I answer this questio in simple EnlishCan I answer this questio in simple Enlish（ ） this question （）（）in simple Enlish 变为被动态 怎么改 求经过点A{3,√3}b{2,3}的椭圆的标准方程 英语翻译I have to get John to download them as when i try it says I need tools..so its better if he does it since he is more into IT.我这么翻译可以吗：因为我下载的时候提示需要工具,我只好让John帮我下载,因为他对 英语翻译China's leaders pledged to inject more risk into a financial system used to bailouts and other support as Beijing sought to advance changes.used to 这句是什么成分 怅惘造句不要抄的 It was in 2008 that she was still in college,这种说法为什么错误? 分生区中期细胞属于原核细胞还是真核细胞? 帮忙找出错误的句子纠正.It was his first day in the mountains that winter.The mist was thickening as darkness fell.Being only a five-minute walk to the village,there was no reason to feel afraid.He picked up his shopping basket and left the 帮帮忙Jack does't like a mouse,He's( )of a mouse.填动词的顺便整句翻译一下 造句.……不仅在于……更因为……： 精雕细棵刻的相对成语是啥哦? 关于“晚成大器”的成语,帮我找一个!这是我们这个星期的作业,要在今天内回答! Abilities是什么意思' Abilities by the time i see you again i ___from that schoolhave graduatedgraduatewill have graduatedgraduated "Abilities"的中文意思和音标是什么 abilities的中文意思 abilities 怎么读,中文是 能力 意思, 1/(x-1)=3/(2x-3)的解 如何降低员工离职率? 2222-3333 降低新员工离职率对企业有哪些好处