You should be aware that online courses contain many errors, probably because whoever sets the questions doesn’t proof-read the online presentations. This confuses students who are already struggling with course materials and problems. I discovered that only when the owners of the course website are told of errors, they issue at the most an apology and perhaps credit the student with marks, but they usually fail to correct the course material. You should take this up with your school or college tutors when education facilities reopen. Amongst the questions you have submitted to MHA, there seem to be a number of typing errors in the actual questions as presented to you online. And, by the way, I hope you are attempting to do your homework yourself and are not using this website to get quick answers, but only to seek help when you’re stuck. I’m willing to help genuine efforts to understand and tackle math questions, on the understanding that you are willing to learn. Keep safe!