Addition and Subtraction of Algebraic Fractions
Big Idea: Adding and subtracting algebraic fractions (rational expressions) follows the same logic as numerical fractions — you need a common denominator. The key difference is that our denominators now contain variables, making factoring an essential skill.
1. Quick Review: Numerical Fractions
Recall that $\frac{2}{5} + \frac{1}{3} = \frac{6}{15} + \frac{5}{15} = \frac{11}{15}$. We found the LCD (15) and rewrote each fraction. The exact same process applies to algebraic fractions.