One's deceased father grind mathematics, always make mistakes when doing problems, what should I do? Obviously, the formula is correct, but it can't get the correct result.
This can only be a snack, the thinking is clear, and it can't be sloppy. I can't say this, just be serious. Anyway, your formulas are listed. See what goes wrong every time. Just pay attention to them in the future. If necessary, you can take a small notebook with the wrong title, and it's okay to flip through it casually. Hope to adopt