170+а=869
а=869-170
а=699
с-841=108
с=108+841
с=949
1)170+a=869
a=869-170
a=699
2)с-841=108
с=841+108
170+а=869
а=869-170
а=699
с-841=108
с=108+841
с=949
1)170+a=869
a=869-170
a=699
2)с-841=108
с=841+108
с=949