the DBMS will first change the sign of the value in the balance column and then multiply it by the value in the tax_rate column. When more than one operator of the same precedence appears in the same expression, they are evaluated from left to right. Therefore, in the expression Sign in...
The unary operators operate on the object for which they were called and normally, this operator appears on the left side of the object, as in !obj, -obj, and ++obj but sometime they can be used as postfix as well like obj++ or obj--....