1391.
1)-9ab
2)0,5cd
3)20mn
4)-6xyz
<span>3*(2-х)-(5 х +4)=0,4-16х
6-3х-5х-4=0,4-16х
2-8х=0,4-16х
16х-8х=0,4-2
8х=-1,6
х=-0,2</span>
1) (<span>10²+11²+12²):73+895=(100+121+144):73+895=365:73+895=5+895=900
2) </span><span>2555:(13²+14²)+35=2555:(169+196)+35=2555:365+35=7+35=42</span>