15300+х=20000
х=20000-15300
х=4700
15300+4700=20000
75900-у=45000+5000
75900-у=50000
у=75900-50000
у=25000
75900-25000=50000
15300+х=20000
х=20000-15300
х=4700
15300+4700=20000
75900-у=45000+5000
75900-у=50000
у=75900-50000
у=25000
75900-25000=50000