Question

How to write the expression 3m-4n-8 as a sum?

Answer 1

3 m - 4 n - 8 
in sum we will use addition symbol i.e plus
so
( 3 m )+ ( -4 n ) + ( - 8) answer...
   as we know that + . - =  - 
so by opening brackets we will again have the given value i.e 3m - 4n - 8..

Answer 2

$\boxed{3m-4n-8=3m+(-4n)+(-8)}$