how to substract decimal values in the razor view in .net core

Your code should be like below

@{   
    var totnet = 0;  
}  
@foreach (var item in (ViewBag.data))  
 {   
     if (item.Name=="")  
     {  
         // do something  
      }  
    else if (item.StoreName == "abc")  
    {  
         totnet = Convert.ToDecimal(@item.TotalPriceWithTax) - Convert.ToDecimal(@item.Return);  
    } 
    @totnet
}

not getting please once check this 

@foreach (var item in (ViewBag.data))
{
else if (@item.StoreName == "abc")
{
var totnet = Convert.ToDecimal(@item.TotalPriceWithTax) - Convert.ToDecimal(@item.Return);
}
@totnet 
} 

Getting 

@{
Convert.ToDecimal(item.TotalPrice)-Convert.ToDecimal(item.Return)
}

; expected error in the line 2 end