Simplification - Facts and Formula

"BODMAS" Rule: This rule depicts the correct sequence in which the operations are to be executed,so as to find out the value of a given expression.
Here, 'B' stands for 'bracket' ,'O'for 'of' , 'D' for' division' and 'M' for 'multiplication', 'A' for 'addition' and 'S' for 'subtraction'.

Thus, in simplifying an expression, first of all the brackets must be removed, strictly in the order(), {} and [].

After removing the brackets, we must use the following operations strictly in the order:
- of
- division
- multiplication
- addition
- subtraction.
Modulus of a real number : Modulus of a real number a is defined as
|a| ={a, if a>0

-a, if a < 0

Thus, |7|=7 and |-7|=-(-7)=7.
Virnaculum (or bar): When an expression contains Virnaculum, before applying the 'BODMAS' rule, we simplify the expression under the Virnaculum.