Ok, I have a question.

When I lift, for example: Bench, I start out with 135, and I do 4 sets of 10 reps, 4x10. I rest for 30 sec's after every lift. Something called helocentric, something like that my math teacher was discussing with me, had to do with weight lifting....so the first is easy, 2nd is little harder, 3rd is hard, 4th is hell. I've been doing this for near 3 weeks now. I up the weight once in a while, but I do the same weight through out the work out, but lately, I have'nt seen that I can lift higher weight. Post here guys what I should do to get stronger, able to lift more weight. I know how to build the muscle....and mass. Just need to focus more on upping the weight in strengh. Thanks.