Researchers identified college students who generally were procrastinators or​ non-procrastinators. The students were asked to report how many symptoms of physical illness they had experienced throughout the semester. By the end of the​ semester, most students had had some symptoms of physical illness regardless of their planning skills. The number of​ symptoms, y, reported for​ non-procrastinators was summarized in the​ function, equals.2x plus 6.5​, where x stands for the number of passed weeks of the semester.​ Similarly, equals.9xplus3 for procrastinators. Find the week in the semester where both groups of students reported the same number of symptoms.