Let f(x)=1/x and g(x)=x^3. find f(x) -g(x)

Amerchant has coffee worth $60 a pound that she wishes to mix with 50 pounds of coffee worth $90 a pound to get a mixture that she will sell for $70 a pound. how many pounds of the & 60 coffee should be used?

How do you write something in scientific notation?

Apackage of five erasers cost 0. $.39 at this rate how many how much would 60 erasers cost in dollars and cents