8,5-7,3+

It looks like the expression is a bit ambiguous because of the trailing plus sign. Here are the likely interpretations:

• If comma is a decimal separator (European style): 8,5 - 7,3 = 1,2
• If dot is a decimal separator (standard in many places): 8.5 - 7.3 = 1.2

If the plus sign means there should be another term after it (e.g., 8.5 - 7.3 + x), please provide the rest and I’ll finish the calculation. Could you confirm which interpretation you intended?