In algebra and math in general one of the most important thing is practice. As the saying goes practice makes man perfect. If you think you have gotten to the roots of math by understanding a concept you might just be telling yourself lies if you dont spend some time actually applying the concept you understand. Algebra seems to be one of the most difficult subjects to many students mainly because even though the normally assume they understand what was taught in class they are unable to solve any question.
Even if your understanding is at top level it would require you a lot of time to solve a question that you have never seen before than one that you know exactly where to start and what to excpect. There a countless of sites that makes this possible
A site that helps in the word problem practice is freemathgenius.com.
You can also always check google for more sites that are tailored to your specific needs. you would not miss one
there are many video sites like youtube that can equally help you out in that field