Find the value of $w=|x-3|-|x+5|-|-x-4|$, knowing that $1<x<3$

Question

I have no idea how to even begin this problem. The answer is $-3x-6$

Answer 1

Hint:

$$1<x<3\implies |x-3|=3-x\,,\,|x+5|=x+5\,,\,\,|-x-4|=x+4\;\text{(why?), so...}$$

By the way, you don't find " a value for $\;w\;$" , just an expression depending on $\;x\;$ .