18000+х+300=20000 900000-800-х=100000 75900-у=45000+5000
1)1800+x+300=20000 2)900000-800-x=100000 3)75900-y=45000+5000 x=20000-1800-300 x=900000-800-100000 75900-y=50000 x=20000-2100 x=799200 y=75900-50000 x=17900 y=25900
18000+x-300=20000 x=20000-18000+300 x=2300 2)900000-800-x=100000 -x=100000-900000+800 -x=-720000 x=720000 3)75900-y=45000+5000 -y=50000-75900 y=25900