х = 16/21
Пошаговое объяснение:
х+4/21=2/3+2/7
х + 4/21 = (2*7+2*3)/21
х + 4/21 = 14/21 + 6/21
х + 4/21 = 20/21
х = 20/21 - 4/21
х = 16/21
Пошаговое объяснение:
х+4/21=2/3+2/7
х + 4/21 = (2*7+2*3)/21
х + 4/21 = 14/21 + 6/21
х + 4/21 = 20/21
х = 20/21 - 4/21
х = 16/21