a, 178 593 + 5x = 427 158
5x = 427 158 - 178 593
5x = 248 565
x = 248 565 : 5
x = 49 713
b, 976 318 - x : 2 = 764 280
x : 2 = 976 318 - 764 280
x : 2 = 212 038
x = 212 038 x 2
x = 424 076
a) 178593 + x × 5 = 427158
=> 5x = 427158 - 178593
5x = 248565
=> x = 248565 : 5
x = 49713
b) 976318 - x : 2 = 764280
=> - x : 2 = 764280 - 976318
- x : 2 = - 212038
=> x = - 212038 × (-2)
x = 424076