Verified answer

53,76 : (4,248 - 1,56х) + 3,8 = 55

53,76 : (4,248 - 1,56х) = 55 - 3,8

53,76 : (4,248 - 1,56х) = 51,2

4,248 - 1,56х = 53,76 : 51,2

4,248 - 1,56х = 1,05

1,56х = 4,248 - 1,05

1,56х = 3,198

х = 3,198 : 1,56

х = 2,05

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Проверка:

53,76 : (4,248 - 1,56 * 2,05) + 3,8 = 55

53,76 : (4,248 - 3,198) + 3,8 = 55

53,76 : 1,05 + 3,8 = 55

51,2 + 3,8 = 55

55 = 55