Brackets

Use of Grouping Symbols
Sometimes in a given expression, the terms are distributed in various groups, using grouping symbols, namely
Parenthesis (  );
Braces {   }
Brackets [  ]

In such groups, parenthesis from the innermost part followed by braces and they then covered by brackets
So we first simplify the term contained in the parenthesis and then those in a brace and then those contained in the brackets.

Sometime we may use the symbol– called bar or vinculum which in order comes and then those contained in the brackets.

Rule 1:If a grouping symbol is preceded by a plus sign, we may remove it by simply writing its terms as they are.

Rule 2: If a grouping symbol is preceded by a minus sign, we change positive signs within it to negatives and vice-versa.

Rules 3: A bracket with a term before it may be removed by multiplying each term in the bracket by the term before it.