1) (39 - х) - 84 = 78
39 - х - 84 = 78
-х = 78 - 39 + 84
-х = 123
х = -123
2) (х - 83) + 316 = 425
х - 83 + 316 = 425
х = 425 + 83 - 316
х = 26
3) (600 - х) - 92 = 126
600 - х - 92 = 126
-х = 126 - 600 + 92
-х = -382
х = 382
1) (39 - х) - 84 = 78
39 - х - 84 = 78
-х = 78 - 39 + 84
-х = 123
х = -123
2) (х - 83) + 316 = 425
х - 83 + 316 = 425
х = 425 + 83 - 316
х = 26
3) (600 - х) - 92 = 126
600 - х - 92 = 126
-х = 126 - 600 + 92
-х = -382
х = 382