Rational algebraic expression (computer science)

This document discusses addition and subtraction of rational algebraic expressions, which are fractions with polynomial numerators and denominators. It explains that rational expressions with like denominators can be added or subtracted by combining only the numerators and keeping the same denominator. Rational expressions with unlike denominators require finding a common denominator before performing the operations. Examples are provided of adding and subtracting rational expressions with both like and unlike denominators.