Since we have reflected only across the y-axis we know the x-values stay the same (but since they are changing quadrants will become positive) and the same goes for the y-values. Only the negative/positive area will change. Lets get to work:
P(-2, -4) will become P'(2, -4)
Q(-3, -1) will become Q'(3, -1)
R(-4, -4) will become R'(4, -4)
After doing this for a while you will be able to find the reflected coordinates without any trouble or graph.
Key point: Values stay the same
