重心是什么的交点

6000（1-x）^2=3600的解是多少?百分比又是多少? 已知x2+y2+4x-8y+20=0先化简再求值(x-y)2(x+y)2-(x2+y2)2 若x2-4x+y2-8y+√﹙z-3﹚+20=0试求代数式(xy)z次方的值 圆x2+y2=16和圆x2+y2-4x+8y+4=0关于直线l对称,则l的方程为 若x2次方+y2次方+4x—8y+20=0,求分式xy分之x2次方—y2次方大神们帮帮忙 人教版必修三英语书第七页答案 物理学（第五版）习题分析与解答马文蔚主编的（有图有真相）这本习题全解的配套课本什么样子,有图最好,没图的描述下 （有图有真相） 关于x的不等式组x-m 按实际情况回答问题How old is your mother?Do you often watch TV?Does your father ofteg cook in the evening?What's your favourite food?Are you good at swimming?ofteg 写错了,是often. 按实际情况回答下列问题.Do you like watching TV?Does your mother like listening to music?What's your favourite TV programme?Are you enjoying cartoon films?Do you like singing? 根据实际情况回答问题1.What was your grandpa before?2.What season is it now?3.What can you do in the library?4.What did you have for lunch yesterday?5.what will you do in National Day? 按实际回答问题What does our national flag look like. 根据实际回答问题1.how ola are you?2.what's your favorite month?3.how is the weather in june iin nanping?4.when is your monther's birthday?5.where are you from?6.what do you want to be? 线性代数中方程组的自由向量是指什么,最好能举例说错了，是自由变量。 题目打不好、其实是这样的1÷（1×2）＋1÷（2×3）...1÷（1×2）＋1÷（2×3）＋1÷（3×4）＋...＋1÷（2009×2010）. 求须鲸、齿鲸、蓝鲸的食性. 上面一题,帮我 实验班上有题是这样的：若a=-2,b=-1/2,则2^2n*(ab^n+1)^2 实际功率怎么求? what does sentence “ALL meals free”mean? mean-free-path什么意思?金属材料 Does buying a Windows Vista Capable PC mean that I will receive a free upgrade to Windows Vista?fan yi xia Your monthly traffic quota exceeded!什么意思 从实际情况出发,正确的对待喝处理问题.（成语?） 从实际情况出发,不夸大,不缩小,正确对待处理问题（换一个词语） 已知直线l经过直线2x+y-5=0与x-2y=0的交点p（1）若点A（5,0）到直线l的距离为3,求直线l的方程（2）求点A（5,0）到直线l的距离的最大值在线等 要过程 先谢过了! 已知直线l经过直线2x+y-5=0与x-2y=0的交点,1若点A(5,0)到l的距离为3,求l的方程?2求点A(5,0)到l的距离的最大值? 过p(1.2)的直线把圆x²+y²－4x－5＝0分成两个弓形,当其中劣弧最短时直线的方程为? 你的字迹与你的姐姐的字迹不一样.Your writing ______ _______ _______ your sister’s is your sister writing carefully in the study这句话有什么错误? 空集是任何非空集合的子集,