A and B in algebra stand for any variables of real numbers. A real number is a value of a continuous quantity that can represent a distance along a line. So if you see A and B in doing your algebra it is just a representation of a value that you need to find.
Where did you live two months ago? a year ago I lived in puebla. a month ago I live in monterrey. Two months ago I lived in Acapulco. Two years ago I lived in Guadalajara.
