124-(х+120)=1 965+(316-х)=1000 3208-(х-784)=3208

124 - (х + 120) = 1                             965 + (316 - х) = 1000

х + 120 = 124 - 1                                316 - х = 1000 - 965

х + 120 = 123                                     316 - х = 35

х = 123 - 120                                      х = 316 - 35

х = 3                                                   х = 281 

Проверка: 124 - (3 + 120) = 1           Проверка: 965 + (316 - 281) = 1000

                   124 - 123 = 1                                     965 + 35 = 1000

3208 - (х - 784) = 3208

х - 784 = 3208 - 3208

х - 784 = 0

х = 0 + 784

х = 784

Проверка: 3208 - (784 - 784) = 3208

                  3208 - 0 = 3208

124 - (х+120)=1;
х+120=1+124;
х+120=125;
х=125-120;
х=5.
965+(316-х)=1000;
316-х=1000-965;
316-х=35;
х=316-35;
х=281.
3208-(х-784)=3208;
х-784=0;
х=787.