6877 -х = 209*4
6877 - х = 836
х = 6877-836 = 6041
проверка 6877-6041 = 836
а + 354 = 412 + 48
а+354=460
а = 460-354 = 106
проверка 106+354 = 460
29400/ х = 700*21
29400/х = 14700
х=29400/14700 = 20
проверка 29400/20 = 14700
419 + х = 209*4
419 + х = 836
х=836-419 = 417
проверка 418+417=836
