1x + 22=3x+45 what tells me if the answer will be negative or positive?

There isn't really a solid way of knowing whether an answer will be negative or positive. The best way to know is just to solve. But to quickly have a sketch in mind you can throw all the constants to one side and x factor to the other and if either will turn out negative and the other positive then it's negative or if both are positive or both negative then the answer will be positive.

If you have any more questions please post. =]