I'm not really a lawn guy. I spend more time trying to kill bermuda so it isn't growing around my fruit trees. But here is my 2 cents.
not sure about which kind of weed it is, there are a few kinds of grass and even sedge can look like that. The best way to get rid of it is to get your bermuda growing better. Bermuda is a very agressive crowder and will crowd out the weeds if it is growing strong and mown regularly. You may need a bit more water, and put down a light feeding. (not to much in this hot weather)