Keeping our data safe and secure is necessary in today's world, but a lot of the encryption we depend on has been in development for thousands of years!

Substitution reactions can have really powerful effects, both good and bad, in our bodies. You might remember substitution reactions as displacement reactions from general chemistry, but (you guessed it!) in organic chemistry they’re a...

Organic chemistry isn’t that different from an adventure game, with substrates as characters, nucleophiles as magic potions, and reaction conditions as different magical kingdoms. In this episode of Crash Course Organic Chemistry, we’ll...

We’ve already learned a bit about substitution reactions in organic chemistry and the two different paths they can follow: SN1 and SN2. In order to better predict the products of a substitution reaction and understand how they work, we...

Join the Amoeba Sisters as they explain gene and chromosome mutations, and explore the significance of these changes. This updated video has improved audio and images! Codons and the amino acids they code for is represented by standard...

We’ve already learned a lot about electrophilic aromatic substitution (EAS) and benzene, but guess what? There’s even more to learn! In this episode of Crash Course Organic Chemistry we’ll revisit our old friends the Friedel-Crafts...

Paul Andersen describes the major mutations found in the living world. He starts with an analogy comparing the information in DNA with the information in a recipe. Changes in the DNA can result in changes to the protein, like changes in...

In this video Paul Andersen explains how metallic solids form when delocalized electrons hold the positive nuclei in an electron sea. This model helps to explain the properties of metals like conductivity, shiny appearance, malleability,...

This video tutorial demonstrates how to use custom substitutions in Google Docs to save time and increase efficiency while typing long phrases repeatedly. The instructor explains the process of setting up custom substitutions by...

A video entitled "Solve Real World Situations" that covers solving a system of equations modeled by a real-world situation and interpreting the solution.

Save money on your prescriptions and ensure safety by following these guidelines.

Pupil outcome: I can use a graphical representation to show all of the points (within a range) that satisfy a relationship. Key learning points: - A line can be drawn using coordinates found following a rule. - You can check any point on...

Pupil outcome: I can use my knowledge of simultaneous equations to solve problems in context and interpret the solutions. Key learning points: - The features of the equations may mean one method is more preferable for solving. - You can...

Pupil outcome: I can substitute particular values into a generalised algebraic statement to find a sense of how the value of the expression changes. Key learning points: - Expressions and formulae in context can be evaluated for...

Pupil outcome: I can solve two (one linear, one quadratic) simultaneous equations algebraically using substitution. Key learning points: - Consider which variable to make the subject for the substitution. - Depending which variable you...

Pupil outcome: I can use my knowledge of simultaneous equations to solve problems. Key learning points: - Where a problem gives multiple ways of connecting two things, it may mean simultaneous equations can be written. - If simultaneous...

Pupil outcome: I can determine which method of solving is most appropriate and interpret the solutions (in context). Key learning points: - The features of the equations may mean one method is more preferable for solving. - You can use...

Pupil outcome: I can solve two linear simultaneous equations algebraically using substitution. Key learning points: - You can use your knowledge of changing the subject to rewrite one or both equations. - If one of the variables is the...

Pupil outcome: I can substitute particular values into a generalised algebraic statement to find a sense of how the value of the expression changes. Key learning points: - Expressions and formulae in context can be evaluated for...

In this video, we use substitution to take equations and rewrite them in the form of a quadratic so that we can solve them.

This is the second of two videos on solving systems of equations using the substitution method.

This is the first of two videos on solving systems of equations using the substitution method. Make sure to watch "Solving Systems by Substitution 2" for help with solving systems when both equations are in standard form!

This video practices solving systems of equations by substitution and elimination.

Welcome to our complete high school mathematics tutorial series! Whether you’re a student preparing for exams, a teacher seeking additional resources, or a parent helping your child succeed in math, these videos cover a wide range of...