Infix notation is the common arithmetic and logical formula notation, in which operators are written between the operands they act on (e.g. 2 + 2)
In infix notation, unlike in prefix or postfix notations, parentheses surrounding groups of operands and operators are necessary to indicate the intended order in which operations are to be performed.
In the absence of parentheses, certain precedence rules determine the order of operations.
3+4*5 = ?
(3+4)*5 or 3+(4*5)
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