Worked examples identifying the equations and slope of horizontal and vertical lines. Watch the next lesson: https://www.khanacademy.org/math/high-school-math/math1/math1-two-var-eq/math1-slope-intercept-form/v/slope-intercept-form?utm_source=YT&utm_medium=Desc&utm_campaign=highschoolmath Missed the previous lesson? https://www.khanacademy.org/math/high-school-math/math1/math1-two-var-eq/hor-and-ver-lines-math1/v/slope-of-a-line-3?utm_source=YT&utm_medium=Desc&utm_campaign=highschoolmath High School Math on Khan Academy: Did you realize that the word "algebra" comes from Arabic (just like "algorithm" and "al jazeera" and "Aladdin")? And what is so great about algebra anyway? This tutorial doesn't explore algebra so much as it introduces the history and ideas that underpin it. About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit www.khanacademy.org, join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything. ... https://www.youtube.com/watch?v=J43CIbKpdWc Note: All Khan Academy content is available for free at (www.khanacademy.org)

Lindsay regroups whole numbers by their place values. Practice this yourself on Khan Academy right now: https://www.khanacademy.org/math/cc-fourth-grade-math/cc-4th-place-value-rounding/cc-4th-num-forms/e/understanding-whole-number-representations Watch the next lesson: https://www.khanacademy.org/math/cc-fourth-grade-math/cc-4th-place-value-rounding/cc-4th-comparing-multi-digit-numbers/v/comparing-whole-number-place-values Missed the previous lesson? https://www.khanacademy.org/math/cc-fourth-grade-math/cc-4th-place-value-rounding/cc-4th-num-forms/v/regrouping-numbers-intro-various-place-values 4th grade math on Khan Academy: 4th grade is the time to start really fine-tuning your arithmetic skills. Not only will you be a multi-digit addition and subtraction rockstar, but you'll extend the multiplication and division that you started in 3rd grade to several digits. You'll also discover that you sometimes have something left over (called a "remainder") when you divide. In 3rd grade you learned what a fraction is. Now you'll start adding, subtracting, multiplying, and comparing them. You'll also see how they relate to decimals. On other fronts, you'll learn how to convert between different units (which is super important when comparing the size and speed of robot unicorns in different countries) and continue your journey thinking about various shapes in two dimensions. Some of the foundational concepts of geometry (like lines, rays and angles) also get introduced. As always, we'll round this out with a healthy dose of applied word problems and explorations of number patterns and properties (including the ideas of factors, multiples and prime numbers). The fun must not stop! (Content was selected for this grade level based on a typical curriculum in the United States.) ... https://www.youtube.com/watch?v=i7lqWXKuhhQ Note: All Khan Academy content is available for free at (www.khanacademy.org)

In 1942, the United States begins to fully engage against the Japanese and go on the offensive. Watch the next lesson: https://www.khanacademy.org/humanities/world-history/euro-hist/wo/v/1942-tide-turning-in-world-war-ii-in-europe?utm_source=YT&utm_medium=Desc&utm_campaign=worldhistory Missed the previous lesson? https://www.khanacademy.org/humanities/world-history/euro-hist/wo/v/1941-axis-momentum-accelerates-in-ww2?utm_source=YT&utm_medium=Desc&utm_campaign=worldhistory World history on Khan Academy: From the earliest civilizations to the modern world, geography, religion, trade, and politics have bound peoples and nations together — and torn them apart. Take a journey through time and space and discover the fascinating history behind the complex world we inhabit today. 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=CBHfoQsF2Y4 Note: All Khan Academy content is available for free at (www.khanacademy.org)

Some more exact equation examples. Watch the next lesson: https://www.khanacademy.org/math/differential-equations/first-order-differential-equations/exact-equations/v/exact-equations-example-3?utm_source=YT&utm_medium=Desc&utm_campaign=DifferentialEquations Missed the previous lesson? https://www.khanacademy.org/math/differential-equations/first-order-differential-equations/exact-equations/v/exact-equations-example-1?utm_source=YT&utm_medium=Desc&utm_campaign=DifferentialEquations Differential Equations on Khan Academy: Differential equations, separable equations, exact equations, integrating factors, homogeneous equations. 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=utQi1ZhF__Q