In order that a $10000 investment grow to $20000 in seven years, what must be the annual rate of interest? Seven years could be called the doubling time for this investment. Notice that it is being assumed that the interest is compounded.

Jackie purchased 3 bottles of water and 2 cups of coffee for a family for $7.35. brian bought 4 bottles of water and 1 cup of coffee for his family for $7.15. how much does each bottle of water cost? how much does each cup of coffee cost? i need this done

36x2 + 49y2 = 1,764 the foci are located at: (-√13, 0) and (√13,0) (0, -√13) and (0,√13) (-1, 0) and (1, 0)edit: the answer is (- the square root of 13, 0) and (the square root of 13, 0)

Xy x xy if a and b are positive integers such that a*b=9 and b*a=72 what is the value of a/b