965-(689-x)=378 28*(135-4z)=756
1) 965-(689-х)=378 689-х=965-378 698-х=587 х=698-587 х=111 2) 28*(135-4z)=756 135-4z=756:28 135-4z=27 4z=135-27 4z=108 z=108:4 z=27