Which expression is equivalent to 3^2*3^-5 a.1/3^3 b.1/3^7c.1/3^-3d.1/3^-7

On a trip, you had to change your money from dollars to british pounds.  you got  560  pounds for  800  dollars.  which is a unit rate that describes the exchange

What are different types of statistical programs

Let f(x) = 3 − x . find the average rate of change of f(x) from x = a to x = a + h and simplify your answer so that no single factor of h is left in the denominator.