@Abcd I just solved it and you may check in case you need solution.
Can anyone help me understanding some symbols I am very poor in getting symbols in functions. Is there any chart or any thing like that I really get scared when I see symbols
This means that we're looking at x in the interval [-2, 0] (since we have the condition x <= 0). Now in this interval, |x| = -x since x <= 0. So it wants to know for what x is f(x) = -x in [-2, 2].