A system of linear equations usually has a solution that is an ordered pair (x,y). Sometimes that isn't the case, especially when the equations represent the graphs of parallel lines (inconsistent system) or the same line (dependent system). Learn how to solve a system of equations algebraically in this free video lesson. 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 or study for that next big test).