(420+х)+300=1000
420+х+300=1000
х=1000-420-300
х=280
Пошаговое объяснение:
160+(х+250)=8000
160+х+250=8000
х=8000 - 160 -250
х=7590
(420+х)+300=1000
420 + x = 1000 - 300
420 + x = 700
x = 700 - 420
x = 280
160+(х+250)=8000
x + 250 = 8000 - 160
x + 250 = 7840
x = 7840 - 250
x= 7590
