Why is multiplication and division of rational expressions easier to calculate than addition and subtraction. when adding two rational numbers together such as 5/6+3/8 you need to find the least common denominator or you can find any common denominator.What is the simplest way to find a common denominator of two factors even if it is not the least common denominator. If you don't use the least common denominator when adding and subtracting rational numbers or expressions,what will you have to do to simplify your answer.Give an example of a relationship between x and y that is represented by a rational expression