Vary and Twist: Collecting like terms

Not sure how I feel about some of the decisions here. I’ve introduced a bit of index laws towards the end of the sheet. Is this madness? I thought I would add it to reinforce the difference between simplifying powers and simplifying regular expressions. Maybe it’s too much.

As usual here’s my little justification for the first 10 questions.

A simple one to start
If you change the letter, it’s the same process
You can have multiples of terms
And it doesn’t matter where in the expression they occur
You can have 3 terms
And it doesn’t matter where in the expression they occur
Introducing a negative for the first time. At the end to make it easier
But the negative can occur anywhere! Here it actually makes you use negatives unless you collect the terms first
Introducing terms like bc. It’s not the same as b + c
We can do some division
Later questions cover stuff like ab being the same as ba.

I quite like the last question