Решить и сделать проверку (450 :х+50):70=2
(450 :х+50):70=2
(450 :х+50)=2* 70
450 :х+50=140
450 :х = 140 - 50
450 :х = 90
х = 450 : 90
х = 5
Проверка
(450 : 5 + 50) : 70 = (90 + 50) : 70 = 140 : 70 = 2
2 = 2
450 : Х + 50 = 2 * 70 = 140
450 : Х = 140 - 50 = 90
Х = 450 : 90 = 5
(450 : 5 + 50) : 70 = 140 : 70 = 2