We are given expression : mn – 11 mn + 3 .
We need to find like terms in order to add or subtract the polynomials.
Like terms are the terms those have same variables.
In the given polynomial, we have first term mn and second term -11mn.
Both of the terms has mn variables with them.
So, we can subtract mn - 11mn.
mn could be written as 1mn.
Therefore, 1mn -11mn = -10mn.
