x +/- 3

is that mroe simplified then writing it out
x + 3, x - 3
I thought it would be becaue we normally say simple is when all of the operations that could be done is done in which case the second choice is more simple? I'm just woundering because i'm doing a summer assignment and have no idea if this teacher is a real jerk in grading and would mark it wrong if I put the first one done becaue it's not as simple as possible if it's not as simple as can be...

I believe you should be able to use either one.