vmaluga2011

Verified answer

(39+х)-84=78
39+х-84=78
х=78+84-39
х=123

(39+123)-84=78
162-84=78
78=78

(х-83)+316=425
х-83+316=425
х=425+83-316
х=192

(192-83)+316=425
109+316=425
425=425

(600-х)-92=126
600-х-92=126
600-92-126=х
х=382

(600-382)-92=126
218-92=126
126=126

253-(х-459)=138
253-х+459=138
253+459-138=х
х=574

253-(574-459)=138
253-115=138
138=138

502-(217-х)=421
502-217+х=421
х=421+217-502
х=136

502-(217-136)=421
502-81=421
421=421

871-(х+157)=385
871-х-157=385
871-157-385=х
х=329

871-(329+157)=385
871-486=385
385=385