E[X]=∑i=1nxipi E[X]=\sum_{i=1}^{n}x_{i}p_{i} E[X]=i=1∑nxipi
E[aX+bY+c]=aE[X]+bE[Y]+c E[aX+bY+c]=aE[X]+bE[Y]+c E[aX+bY+c]=aE[X]+bE[Y]+c
