Jim performs a periodic analysis of his project. He notices the variances his project is experiencing are due to a one time unexpected expense. Considering the variances to date have been atypical, which formula should Jim use in calculating a revised estimate at completion (EAC)?

Ans is given as

EAC = AC+BAC-EV

How to arrive at this, from the formulae known, namely EAC = BAC / CPI and CPI=EV/AC?