Thalia, a quiz show contest, answer 20 questions. She was awarded two points for every correct answer that she gave, but she was penalized one point for every incorrect answer. In the end, Thalia had a total of 28 points. In order to determine the number of correct and incorrect answers that she gave, a view were at home use the system of linear equations X plus Y equals 20 and 2X plus Y equals 28, with ex being the number of correct answers and why being the number of incorrect answers. The view were solve the system by using the linear combination method as shown.