Two bikers, jose and luis, start at the same point at the same time and travel in opposite directions. jose's average speed is 9 miles per hour more than that of luis, and after 3 hours the bikers are 81 miles apart. find the average speed of each biker.

Can any one me with the answers to these questions asap?

Solve this equation using substitution. {4x + y = −2} {4x + 6y = 44}

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?