Question:
Solve $-4 x>16$, when $x \in Z$
Solution:
We have to find integer values of x for which -4x > 16 (why only integer values because it is given that $x \in Z$ that is set of integers)
$-4 x>16$
$\Rightarrow-x>4$
$\Rightarrow x<-4$
The integers less than $-4$ are $-5,-6,-7,-8, \ldots$
Generalizing the solution in terms of n
$x=-(4+n)$ where $n$ is integers from 1 to infinity
Hence solution of $-4 x>16$ is $x=-(4+n) \forall n=\{1,2,3,4 \ldots\}$