70746-(629а+278а)+(22а+80а)=
2000b+(68890b-83b)-(187b+65b)=

1) =(629+278) =907(22+80)=102907+102=100970746-1009=697372) (68890-83)=68807(187+65)=25268807-252=685552000+68555=70555