Để đánh giá mức độ cân đối giữa thời gian học bài ( Y: giờ/ngày ) và thời gian vui chơi ( X: giờ/ngày ), người ta khảo sát 120 học sinh và thu được bảng kết quả sau

Girardo is using the model below to solve the equation . girardo uses the following steps: step 1 add 4 negative x-tiles to both sides step 2 add 1 negative unit tile to both sides step 3 the solution is which step could be adjusted so that gerardo's final step results in a positive x-value? in step 1, he should have added 4 positive x-tiles to both sides. in step 1, he should have added 3 negative x-tiles to both sides. in step 2, he should have added 4 negative unit tiles to both sides. in step 2, he should have added 1 positive unit tile to both sides.