I believe the answer is 11/15 .
Haoyu, I'm telling Ms. Mak about your behavior. Expect not to see tomorrow, you were cheating on the math test. I will also contact your parents. Reply to me immidetly if you do not want to get exposed to everyone.
You can factor out a 2 from all. Idk if that helps but here ya go. 10x+3x-4