Do variables without any number beside them have a coefficient?

Question

I've seen variables like $x, r, z, q, t$ that don't have any numbers beside them. Do they even have coefficients, likewise for negative variables without any numbers in front of the negative signs? I've seen this happen, and it looks like, for these positive variables along, they seem like they have coefficients of one, likewise for negative variables without any numbers beside the negative signs?

Answer 1

They have a coefficient of 1, this fact is used when doing integration by parts of some functions such as actan(x) or (log(x))^2. Same applies to a negative value, it has a coefficient of -1. Which you can take out as a factor to create a positive variable.