Deriving the quadratic formula by completing the square. Watch the next lesson: https://www.khanacademy.org/math/algebra/quadratics/quadratic_odds_ends/v/ca-algebra-i-quadratic-equation?utm_source=YT&utm_medium=Desc&utm_campaign=AlgebraI Missed the previous lesson? https://www.khanacademy.org/math/algebra/quadratics/quadratic_odds_ends/v/quadratic-equation-part-2?utm_source=YT&utm_medium=Desc&utm_campaign=AlgebraI Algebra I on Khan Academy: Algebra is the language through which we describe patterns. Think of it as a shorthand, of sorts. As opposed to having to do something over and over again, algebra gives you a simple way to express that repetitive process. It's also seen as a "gatekeeper" subject. Once you achieve an understanding of algebra, the higher-level math subjects become accessible to you. Without it, it's impossible to move forward. It's used by people with lots of different jobs, like carpentry, engineering, and fashion design. In these tutorials, we'll cover a lot of ground. Some of the topics include linear equations, linear inequalities, linear functions, systems of equations, factoring expressions, quadratic expressions, exponents, functions, and ratios. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. ... https://www.youtube.com/watch?v=mDmRYfma9C0 Note: All Khan Academy content is available for free at (www.khanacademy.org)

An example of simplifying a seemingly complicated resistor circuit. Created by Willy McAllister. Watch the next lesson: https://www.khanacademy.org/science/electrical-engineering/ee-circuit-analysis-topic/ee-dc-circuit-analysis/v/ee-kirchhoffs-current-law?utm_source=YT&utm_medium=Desc&utm_campaign=electricalengineering Missed the previous lesson? https://www.khanacademy.org/science/electrical-engineering/ee-circuit-analysis-topic/ee-resistor-circuits/v/ee-voltage-divider?utm_source=YT&utm_medium=Desc&utm_campaign=electricalengineering Electrical engineering on Khan Academy: A summary of the math and science preparation that will help you have the best experience with electrical engineering taught on Khan Academy. Become familiar with engineering numbers and notation, and learn about the two most important electrical quantities: current and voltage. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. ... https://www.youtube.com/watch?v=j-iR7puLj6M Note: All Khan Academy content is available for free at (www.khanacademy.org)