The midpoint of a segment is(2,1) and one endpoint (8,7).find the coordinates of the other endpoint

If i have 20$ and i gave 5$ away how much i got

Kayla made observations about the sellin price of a new brand of coffee that sold in the three different sized bags she recorded those observations in the following table 6 is $2.10 8 is $2.80 and 16 is to $5.60 use the relationship to predict the cost of a 20oz bag of coffee.

What is always true about a positive integer raised to a negative odd power?