Grace works as a salesperson at an electronics store and sells phones and phone accessories, and makes a fixed commission for each phone sale and a different fixed commission for each accessory sale. Yesterday Grace sold 18 phones and 21 accessories and made a total commission of $204. Today she sold 6 phones and 14 accessories and made a total commission of $82. Determine the price of each phone and the price of each accessory. Show steps when answering.