How to Add rational expressions in algebra

From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework). With this three-part installment from Internet pedagogical superstar Salman Khan's series of free math tutorials, you'll learn how to sum rational expressions in algebra.