Answer:
Since I don't know the question you want answered I'll try to answer this one.
You can often retrace your steps and you might find how to work that problem out. You could also look at similar problems using the same formula to answer the question you don't understand.
Explanation:
next time if you need an answer please post it. it would be very hard to answer a question if you don't say what it is.
Hope this helped anyways!