doubt 4

for x>2
f(x)=2x-4-x-1+x=2x-5
for -1<x<2
f(x)=-2x+4-x-1+x=-2x+3
for x <-1
f(x)=-2x+4+x+1+x=5

now i think the graph can be ploted with above details

simply apply symmetry methods for the first one: a rather easy question !!!

@nix
just apply diff intervals of modulus fn as done by kirti in post#2

like in 2nd ques

Case1
x<0
=>f(x)=x+(-x)=0

Case2
x≥0
=>F(x)=x+(x)=2x

u can draw the graph now