16,3х-(3,8х+7,4)=4,06 ,

16,3х - 3,8х - 7,4 = 4,06,

16,3х - 3,8х = 4,06 + 7,4,

12,5х = 11,46,

х = 0,9168,

проверка:

16,3*0,9168 - (3,8*0,9168 + 7,4) = 4,06,

14,94384 - (3,48384 + 7,4) = 4,06,

11,46 - 7,4 = 4,06,

4,06 = 4,06