1.75=12.3-x/2.8 i tried to solve but said answer is 7.4

The patient was the driver in a motor vehicle collision, a one-vehicle rollover occurred that was caused due to lack of control. the patient is now bleeding into the abdominal cavity. the physician brings this patient to the operating room to remove the spleen in order to control this patient's bleeding. the major vessels of the lacerated spleen were carefully dissected, and the spleen was removed in its entirety? cpt code: icd10-cm code: icd10-cm code