Answer
$n\geq40$ or $n\leq0$
Work Step by Step
$|0.4n-8|+4\geq12\\|0.4n-8|\geq8$ implies $0.4n-8\geq8\\0.4n\geq16\\n\geq40$ or $0.4n-8\leq-8\\0.4n\leq0\\n\leq0$.
Thus $n\geq40$ or $n\leq0$.
Then, by using a graphing utility, the solution set is attached.
![](https://gradesaver.s3.amazonaws.com/uploads/solution/e3c9be15-b56f-4816-848d-ecce4f8df029/steps_image/small_1572873120.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAJVAXHCSURVZEX5QQ%2F20240907%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20240907T235915Z&X-Amz-Expires=900&X-Amz-SignedHeaders=host&X-Amz-Signature=c42980e681fdb3f15b687e42f4bc0ae0e6829d8cc5c8b31e18473633ed9efaf2)