Mr. Zhamad,

Just relax but dont ever yell your kids especially at their teenage generation the moment you get scold them the more revenge wil they act, A good example always start from our home and we as a parents is always a perfect teacher, I guess your teenage boys needs your attention try to talk with them in a nice way and explain properly the effect if they dont finish their study give them few examples from your past bad experiences, You might also need your full bonding with them and always give your time with your family, try to manage your time.

I have my the same situation as yours, me and my wife are both working but it's not an excuse we always talk and discuss for the good future of our kids,they are 2 boys my eldest is 17 and my youngest is 14 years old they also hangout with their friends but what we did instead of get scold them we joined the group but with proper limitations, remember we've been a teenager before try to look at your generation with your parents and from there you'll get an idea on how to handle your kids.