Khan Academy: Product Rule for More Than Two Functions

Can an equation have an infinite number of solutions? Allow your class to discover the relationship between the input and output variables in a two-variable equation. Class members explore the concept through tables and graphs and...

There's more to derivatives of multiplication than simply the product of the derivatives. A helpful video gives learners the product rule of finding the derivative of the product of two functions. Pupils find the derivatives of functions...

Sal adds a few more steps to these problems as he solves algebraic equations with two steps, though he states that "there's more than one way to do it." Those who become confused by increasingly complicated algebra problems on a test...

This video demonstrates how to evaluate an expression with two variables using substitution. [1:46]

Work a problem on adding and subtracting polynomials with two variables. Video is available if you need a hint.

How can we calculate a weighted average between two points? (pssst. This video is super important)

A bar chart is especially useful with comparing two sets of data. The difference in the bars give us a quick snapshot that allows us to draw some conclusions.

This video will show you how to calculate the slope given two points on a line. [7:12]

Follow along with this tutorial to learn how to add two functions together. [4:22]

Graph and solve linear equations in two variables. The class relates the concepts of linear equations to the real world.