The length of a rectangle is four less than three times the width. what is the area of the rectangle?

Ahigh definition tv cost $800 with a down payment of 2/5 of the cost. how much is left to pay, in dollars after the down payment has been made?

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab