Commutative Law of Addition Watch the next lesson: https://www.khanacademy.org/math/pre-algebra/order-of-operations/arithmetic_properties/v/commutative-property-for-addition?utm_source=YT&utm_medium=Desc&utm_campaign=PreAlgebra Missed the previous lesson? https://www.khanacademy.org/math/pre-algebra/order-of-operations/ditributive_property/v/distributive-property-exercise?utm_source=YT&utm_medium=Desc&utm_campaign=PreAlgebra Pre-Algebra on Khan Academy: No way, this isn't your run of the mill arithmetic. This is Pre-algebra. You're about to play with the professionals. Think of pre-algebra as a runway. You're the airplane and algebra is your sunny vacation destination. Without the runway you're not going anywhere. Seriously, the foundation for all higher mathematics is laid with many of the concepts that we will introduce to you here: negative numbers, absolute value, factors, multiples, decimals, and fractions to name a few. So buckle up and move your seat into the upright position. We're about to take off! 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=HwSszh3L358 Note: All Khan Academy content is available for free at (www.khanacademy.org)

Exponent Properties 2 Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/algebra/exponent-equations/exponent-properties-algebra/e/simplifying_expressions_with_exponents?utm_source=YT&utm_medium=Desc&utm_campaign=AlgebraI Watch the next lesson: https://www.khanacademy.org/math/algebra/exponent-equations/exponent-properties-algebra/v/exponent-properties-3?utm_source=YT&utm_medium=Desc&utm_campaign=AlgebraI Missed the previous lesson? https://www.khanacademy.org/math/algebra/exponent-equations/exponent-properties-algebra/v/exponent-properties-1?utm_source=YT&utm_medium=Desc&utm_campaign=AlgebraI ... https://www.youtube.com/watch?v=tvj42WdKlH4 Note: All Khan Academy content is available for free at (www.khanacademy.org)

Photoelectric materials emit electrons when they absorb light of a high-enough frequency. Khan Academy is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We offer quizzes, questions, instructional videos, and articles on a range of academic subjects, including math, biology, chemistry, physics, history, economics, finance, grammar, preschool learning, and more. We provide teachers with tools and data so they can help their students develop the skills, habits, and mindsets for success in school and beyond. Khan Academy has been translated into dozens of languages, and 15 million people around the globe learn on Khan Academy every month. As a 501(c)(3) nonprofit organization, we would love your help! Donate or volunteer today! Donate here: https://www.khanacademy.org/donate Volunteer here: https://www.khanacademy.org/contribute ... https://www.youtube.com/watch?v=3O0xl8f2mSs Note: All Khan Academy content is available for free at (www.khanacademy.org)

We can explain why a function is increasing, decreasing, or having a relative maximum using information about its first derivative. This is called calculus-based justification. Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/ap-calculus-ab/ab-derivatives-analyze-functions/ab-justification-with-first-derivative/e/justification-using-first-derivative-test?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusAB Watch the next lesson: https://www.khanacademy.org/math/ap-calculus-ab/ab-derivatives-analyze-functions/ab-justification-with-first-derivative/v/calculus-based-justification-for-function-increasing?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusAB Missed the previous lesson? https://www.khanacademy.org/math/ap-calculus-ab/ab-derivatives-analyze-functions/ab-justification-with-first-derivative/v/relative-minima-maxima?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusAB AP Calculus AB on Khan Academy: Bill Scott uses Khan Academy to teach AP Calculus at Phillips Academy in Andover, Massachusetts, and heÕs part of the teaching team that helped develop Khan AcademyÕs AP lessons. Phillips Academy was one of the first schools to teach AP nearly 60 years ago. ... https://www.youtube.com/watch?v=t-RXwwBjxsc Note: All Khan Academy content is available for free at (www.khanacademy.org)