First, it is important to note that , since you can not have the square root of a negative number.
Putting it all together, we have our solution set
Notice that if you use any number less than 4, you need to use the NEGATIVE square root to make the sentence make sense...
That isn't a correct solution set.
Substitute some values back into the inequality. For example if x=1, the inequality isn't true.
-4(-1)+4=8 which isn't greater than 12.
-4(1)+4=0 which isn't greater than 12.
The answer is x>4, but how do we arrive at that?