2. A coin purse contains d dimes and quarters. There are 20 coins in the purse, and the total value of the coins is $4.25. Which system of equations represents this situation?

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

Answer each of the questions for the following diagram: 1. what type of angles are these? 2. solve for x. what does x equal? 3. what is the measure of the angles?

What is the area of the shaded sector?