(28/31+х)-14/31=16/31
(28/31+х)-14/31=16/31 28/31+х-14/31=16/31 х=16/31-28/31+14/31 х=2/31
(28/31+х)-14/31=16/31 28/31+х=14/31+16/31 28/31+х=30/31 х=30/31-28/31 х=2/31