What is 3.24 repeating as a mixed number

What is the number 321,000,000 in scientific notation? also what is the number? ?

What is the difference between the equations of a vertical and a horizontal line?

You just purchased two coins at a price of $670 each. because one of the coins is more collectible, you believe that its value will increase at a rate of 7.1 percent per year, while you believe the second coin will only increase at 6.5 percent per year. if you are correct, how much more will the first coin be worth in 15 years?