Atest contains multiple choice questions and short answer questions. the short answer questions are worth more than the multiple choice questions. one student answers 17 multiple choice questions correctly and four short answer questions correctly and scores 71 points. another student answers 15 multiple choice questions correctly and eight short answer questions correctly, and scores 85 points. if you create a system of equations to represent these test results, and you use elimination to solve it, which equation below could be used to determine how much the multiple choice questions are worth?