Rachel
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Khan Academy on a Stick

Algebra

Factoring special products

You will encounter very factorable quadratics that don't always seem so. This tutorial will expand your arsenal by exposing you to special products like difference-of-squares and perfect square quadratics.

Multiplying and dividing monomials

"Monomials" sounds like a fancy word, but it just refers to single terms like "4x" or "8xy" or "17x^2z". In this tutorial, we'll learn to multiply and divide them using ideas you're already familiar with (like exponent properties and greatest common factor).

Multiplying binomials

In this tutorial you'll learn that multiplying things like (4x-7)(-9x+5) just require the distributive property that you learned in elementary school. We'll touch on the FOIL method because it seems to be covered in a lot of schools, but we don't like it (we don't think it is good to memorize processes without knowing the why).

Factoring simple expressions

You already know a bit about multiplying expressions. We'll now reverse course and look at how to think about an expression as the product of simpler ones (just like we did when we find the factors of numbers).

Factoring quadratic expressions

Not only is factoring quadratic expressions (essentially second-degree polynomials) fun, but it is good for you. It will allow you to analyze and solve a whole range of equations. It will allow you to impress people at parties and move up the career ladder. How exciting!

Factoring by grouping

Factoring by grouping is probably the one thing that most people never really learn well. Your fate doesn't have to be the same. In this tutorial, you'll see how factoring by grouping can be used to factor a quadratic expression where the coefficient on the x^2 term is something other than 1?

Factoring quadratics in two variables

We'll now extend the application of our quadratic-factoring toolkit, by factoring expressions with two variables. As we'll see, this is really just an extension of what you probably already know (or at least will know after working through this tutorial). Onward!

Polynomial basics

"Polynomials" sound like a fancy word, but you just have to break down the root words. "Poly" means "many". So we're just talking about "many nomials" and everyone knows what a "nomial" is. Okay, most of us don't. Well, a polynomials has "many" terms. From understanding what a "term" is to basic simplification, addition and subtraction of polynomials, this tutorial will get you very familiar with the world of many "nomials." :)

Multiplying polynomials

You'll see in this tutorial that multiplying polynomials is just an extension of the same distributive property that you've already learned to multiply simpler expression (that's why we think FOIL is lame--it doesn't generalize and it is more memorization than real understanding).

Dividing polynomials

You know what polynomials are. You know how to add, subtract, and multiply them. Unless you are completely incurious, you must be wondering how to divide them! In this tutorial we'll explore how we divide polynomials--both through algebraic long division and synthetic division. (We like classic algebraic long division more since you can actually understand what you're doing.)