1)(208+х)-416=137
(208+х)=137+416
208+х=553
х=553-208
х=345
(208+345)-416=137
553-416=137
137=137
2)(х+506)+215=492
(х+506)=492-215
х+506=277
х=277-506
х=-229
(-229+506)+215=492
277+215=492
492=492
3)(х-164)+308=500
(х-164)=500-308
х-164=192
х=192+164
х=356
(356-164)+308=500
192+308=500
500=500
4)(942-а)-126=154
(942-а)=154+126
942-а=280
а=942-280
а=662
(942-662)-126=154
280-126=154
154=154
5)(801-в)-224=368
(801-в)=368+224
801-в=592
в=801-592
в=209
(801-209)-224=368
592-224=368
368=368