find the value of" A" such that triangle DEF with vertices D (a,1) , E(10,7) and F(7 ,11) is a right angle at E?​

Jody bought 20 shares of amazon at the close price of $121.00. she bought 20 more shares a year later at the price of $127.00. two years later, she sold all of her shares at the price of $133.00. her broker charges $50 for each transaction. after all of these transactions, how much money did jody make?