We need to simplify this expression:
So, we will call this expression as:
We can write this equation like this:
So, if we simplify it, this can be written like this:
f(x) = 4 but given that the denominator can't be zero, then:
∴ 
Therefore:
f(x) = 4 if and only if
So, we will call this expression as:
We can write this equation like this:
So, if we simplify it, this can be written like this:
f(x) = 4 but given that the denominator can't be zero, then:
Therefore:
f(x) = 4 if and only if