do or die

Edit [Moderator]: Moved from English to Science & Mathematics.

plz as quick as possible i m waiting for your responce becoz it is an urgent assignment
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the assignment is of calculus (to prove the properties of absolutes
1:- |-a|=|a|


2:- |ab|=|a| |b|



3:- |a/b|=|a|/|b|



4:- |a+b| less than or equal 2 |a| +|b|