Question

Sum of $3mn,-5mn,8mn$and $-4mn$is ________.

Answer 1

Find the sum of $3mn,-5mn,8mn$and $-4mn$

Here we add the like terms,

$$\begin{gathered} 3mn+(-5mn)+8mn+(-4mn)=3mn-5mn+8mn-4mn \\ =(-2mn)+4mn \\ =2mn \end{gathered}$$

$\therefore$The sum of $3mn,-5mn,8mn$and $-4mn$is $2mn$