Short Answers:
That depends on the state. Each state has its own laws. You would have to look that up. Talk to your parents
Long Answer:
If you are asking whether or not your parents should still allow it that really depends on your situation and what you and your parents already discussed. As you have probably already read many of the parents have a grade standard. While other parents take into account other factors as well. My cousin, for example, wasn't a very good student but he tried hard. He worked, never got into any trouble, spent most of his free time doing extracurricular activities and studying. He was very trustworthy despite his grades so his parents gave him a car. If my child was generally a good student, responsible, and trustworthy, and this was just one area where s/he struggling then I say yes, they still earned it and deserve it. However, if they didn't try hard was unreliable and I just didn't trust their judgment, then of course a failed algebra test would just be one more thing and I'd say of course not. So, talk to your parents and make sure you are responsible and they can trust you or don't bother.