Step-by-step explanation:
The expression is given below as
Concept:
The sum of two or more like terms is a single like term; but the two unlike terms cannot be added together to get a single term. Suppose, to find the sum of two unlike terms x and y, we need to connect both the terms by using an addition symbol and express the result in the form of x + y.
In this case,
The terms given ( 3m and n ) are unlike terms and as such the expression cannot be simplified further
Hence,
The final answer is
such