This video demonstrates converting large numbers from expanded and written form to standard form. Using the example "six hundred forty-five million five hundred eighty-four thousand four …

The standard form for linear equations in two variables is Ax+By=C. For example, 2x+3y=5 is a linear equation in standard form. When an equation is given in this form, it's pretty easy to find …

Writing linear equations in standard form becomes more useful when dealing with more than two variables, especially when solving systems of linear equations.

So now that we have this representation, let's write it out in words and you don't have to do this every time, but I am just trying to make sure we see every possible way of thinking about it.

We can rewrite an equation in slope-intercept form (y=mx+b) to be in standard form (Ax+By=C) instead. In this example, we rewrite the slope-intercept equation y=2/3x+4/7 in standard form.

It's helpful that the equations lead into each other. First is point-slope, then slope-intercept, and lastly standard form.

In this video, we're going to think about going from a number written in words to expanded form. So let's look at an example. Let's say I were to write the following, and I'm not even going to …

So, as long as you write it in Ax + By = C, it can be called standard form. For the safe side, your teacher probably wants the A to be in positive integer value.

Learn how to graph any quadratic function that is given in standard form. Here, Sal graphs y=5x²-20x+15.

Given a circle on the coordinate plane, Sal finds its standard equation, which is an equation in the form (x-a)²+ (y-b)²=r².