双电源转换开关r和n表示什么

1/2-1/6-1/12-1/20-1/30-1/42=?是6/7 还是1/7 1\2+1\6+1\12+1\20+1\30+1\42+1\7 举例说明,钟面角在哪些时刻30°,60°?(2)举例说明,时钟的分针在哪些时刻互相垂直 12-6+6-6+7-1+5+1+1= 30-10+30-10-10+20= 六年级温暖作文700字 英语连词成句：is listening he what to he is listening to music是什么意思 2x+1≥-3和1/3x he is listening to music 改为否定句 music,Steven,to,is,bedroom,in,listening,his连词成句 1、若n满足（n-2010）²+（2011-n）²=1,求（n-2010）（2011-n）的值.2、若a+b-c=3,a²+b²+c²=3,那么a^2008+b^2008+c^2008的值为? 120的20分之1是 120米比（ ）米少20％ at my free time 还是on my free time Her h-- is listening to music in her free time.Her h is listening to music in her free time. 如图,点A,B在反比例函数y=x分之k的图像上,且点A,B的横坐标分别为a、2a,AC⊥x轴,垂足为点C,且三角形AOC的面积为2（1）求该反比例函数解析式.（2）若点（-a,y1),(-2a,y2)在该反比例函数图像上,试比 如图所示,点A,B 在反比例函数y=x分之k的图像上,且点AB的横坐标分别为a,3a(a＞0）,AC⊥x轴,垂足为C,且△AOC的面积为3（1）求该反比例函数的解析式（2）求△AOB的面积. 数学优化7天13题 2x^3+3x^2-1=0怎么求? 数学优化7天10题 6/7*(5/6-1/2)+1/2 简便运算咋算呀?急需 英语翻译我英语考试的时候,时间不够,因为就是读英语短文,做阅读题,我老是读不懂,时间又浪费了,有没有好的方法啊,如果说只有通过练习,我可以,我想事先学一些方法, Do you like listening to music? do you like listening to p() music? 求教数学达人6,7,8题. 证明函数f（x）=1-x方分之一在（-无穷,0）上为增函数 英语翻译During the transition period,the composition of incomes was affected by the following measures:abolishment of the previous confiscated profit transfer tax in 1990 and its replacement with a profit tax,which was reformed in 1991 and again 英语翻译4.IMPACT OF THE FISCAL POSITION ON DEBT SUSTAINABILITY Another important determinant of the debt dynamics that appears in equation (1) is primary fiscal balance.A permanent increase in the fiscal primary surplus,would improve debt sustain 英语翻译It is remarkable to see that Romania has also begun to demonstrate the correlation between election cycles and the accumulation of public debt.We can observe on the presented graphs the jumps occurred in the electoral years,in 1992 and in 设两个有理数的和是a,差是b,那么a与b的关系是什么ab,或a=b a,b为两个有理数,表示 设函数f(x)=sin（x+6分之派）+2sin方二分之x,（1）求最小正周期（2）记三角形ABC的内角为abc,若f(A)=1,c=根号3,求b的值