|18-x|, if x<18. Pls help

I18 - xI such that x < 18.

ok, first let's what happens if x = 18:

I18 - xI = I18 - 18I = 0

So, at the moment we have the condition:

I18 - xI > 0.

now, if x is a really large negative number, suppose, x = -100

I18 + 100I = I118I = 118

So, as x can freely move in the negative range, we can see that I18 - xI can be any positive number, so the only restriction that we have is:

I18 - xI > 0.

This means that the domain is:

D = (-∞, 18)

and the range is:

R = (0, ∞)

the discriminant is 64 + 4*1*12 = 112

this is prime.

step-by-step explanation: