I had changed my front brakes a little more than a year ago and I was lazy so I didn't replace the rears. Well now they have been getting much worse and I need to replace the pads and rotors. My question is when I changed the front brakes I flushed the brake fluid, do I need to do this again when I do the rears? Thanks.

 

You don't need to flush the fluid. You should flush the fluid once a year. Do it more often if you track the car.