Assuming the first question mark is +, then 5/(5+1/2)=5/(11/2)=5*2/11=10/11.
Assuming instead that it's minus, then 5/(5-1/2)=5/(9/2)=10/9=1 1/9.
Assuming instead that it's multiply, then 5/(5*1/2)=5/(5/2)=10/5=2.
Assuming instead that it's divide, then 5/(5/(1/2))=5/10=1/2.
Assuming instead that it's 5/5^(1/2), then the answer is 5^1/2 or 2.236 approx. (square root of 5).