216⋅57+20885⋅(−5)8+(−2)5⋅109
=216⋅57+208215⋅58−25⋅109
=216⋅57+208(210⋅518−109)⋅25
=216⋅57+208(22⋅108−109)⋅25
=216⋅57+208(22−10)⋅108⋅25
=216⋅57+208(4−10)⋅108⋅25
=216⋅57+208−6⋅108⋅25
=216⋅57+208−3⋅2⋅108⋅25
=216⋅57+208−3⋅26⋅108
=216⋅57+208−3⋅64⋅108