quick的副词形式:Math!!!!Math~~~~~

来源：百度文库 编辑：高考问答 时间：2024/05/02 07:57:15
The average of P number is x and the average of N number is y. What is the average of all the (P+N) number?

x+y

(P*x+N*y)/(x+y)

(P+N)*xy /(Py+Nx)

(P*X+N*Y)/(P+N)
加权平均数

Math!!!! Math!!!! Math!!!! MATH!!!!!!! MATH!!!!!!! MATH!!!!!!! Math ! Math ! Math ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!&%@~$^*#!!!!!!!!MATH