จาก E [ X | X 1 i s e v e n ] = E [ X 1 | X 1 i s e v e n ] + E [ X 2 | X 1 i s e v e n ] {\displaystyle E[X|X_{1}iseven]=E[X_{1}|X_{1}iseven]+E[X_{2}|X_{1}iseven]} จาก linearity of expectations
![{\displaystyle E[X|X_{1}iseven]=E[X_{1}|X_{1}iseven]+E[X_{2}|X_{1}iseven]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f69373679c09e5784f6ce15c5f832642cfb0d7f4)
จาก linearity of expectations
