180(simpler)-184, pgs. 176-177. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/test-prep/gmat/problem-solving/v/gmat-math-37?utm_source=YT&utm_medium=Desc&utm_campaign=GMAT Missed the previous lesson? https://www.khanacademy.org/test-prep/gmat/problem-solving/v/gmat-math-35?utm_source=YT&utm_medium=Desc&utm_campaign=GMAT GMAT on Khan Academy: Sal works through the 249 problem solving questions in chapter 5 of the the 11th edition of the official GMAC GMAT Review (ISBN Number: 0-9765709-0-4 published in 2005) 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=x8pEjhCc5ug

Buffers and the Henderson-Hasselbalch equation ... https://www.youtube.com/watch?v=HzmI7A578ss Note: All Khan Academy content is available for free at (www.khanacademy.org)

14-20, simple logical reasoning https://www.youtube.com/watch?v=yIzF_XGX4qk

Using path independence of a conservative vector field to solve a line integral Watch the next lesson: https://www.khanacademy.org/math/multivariable-calculus/line_integrals_topic/greens_theorem/v/green-s-theorem-proof-part-1?utm_source=YT&utm_medium=Desc&utm_campaign=MultivariableCalculus Missed the previous lesson? https://www.khanacademy.org/math/multivariable-calculus/line_integrals_topic/line_integrals_vectors/v/example-of-closed-line-integral-of-conservative-field?utm_source=YT&utm_medium=Desc&utm_campaign=MultivariableCalculus Multivariable Calculus on Khan Academy: Think calculus. Then think algebra II and working with two variables in a single equation. Now generalize and combine these two mathematical concepts, and you begin to see some of what Multivariable calculus entails, only now include multi dimensional thinking. Typical concepts or operations may include: limits and continuity, partial differentiation, multiple integration, scalar functions, and fundamental theorem of calculus in multiple dimensions. 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=LpY8Qa3IP1w Note: All Khan Academy content is available for free at (www.khanacademy.org)