Как проверку?
7,5х-2,46х=78,3+124,56

5,04x = 202,86

x = 40,25

7,5х - 2,46х = 78,3 + 124,565,04х = 202,86х = 202,86 : 5,04х = 40,25________________________7,5*40,25 - 2,46*40,25 = 78,3 + 124,56301,875 - 99,015 = 202,86202,86 = 202,86Ответ: х = 40,25Darknight (Sunny Storm)