5/6×(4,2х-1 1/5 у)-5,4×(2/9 х-1,5у)=
=5/6(21/5х - 6/5у)-27/5(2/9х-3/2у)=
=21/6х-у-54/45х+81/10у=21/6х-54/45х-у+8,1у=(21*15-54*2)/90х+7,1у=2,3х+7,1у
5/6×(4,2х-1 1/5 у)-5,4×(2/9 х-1,5у)=
=5/6(21/5х - 6/5у)-27/5(2/9х-3/2у)=
=21/6х-у-54/45х+81/10у=21/6х-54/45х-у+8,1у=(21*15-54*2)/90х+7,1у=2,3х+7,1у