Today we begin to study the connection between things we draw (geometry) and equations that describe them (algebra). This connection is possible because of the simple but brilliant idea of *plotting points* — here is a review of plotting.

In this class, we will focus on equations of lines. An equation of a line, or **linear equation***,* is an equation that can be written in the form Ax+By=C, called **standard form**. Another useful form of linear equations that you may be familiar with is y=mx+b, or **slope-intercept form**.

There are a lot of resources available on the internet and elsewhere about equations of lines. Here are a few, grouped according to the major topics and types of problems.

We begin with an equation of a line, and draw the graph by finding solutions and plotting points.

One of the key pieces of information that we use in studying lines is the slope. If you need a review of finding the slope of a line, here is a video with a good explanation.

We will be practicing finding equations for lines. These types of problems can vary a bit depending on what information you are given at the start. The following series of videos cover several of the possibilities.

**1. Find equation of a line based on the slope and one point (the y-intercept):** http://youtu.be/AqFwKecNaTk

**2. Find the equation of a line based on the slope and a point (not the y-intercept): **

**3. Find the equation of a line based on two points:** http://youtu.be/XMJ72mtMn4Y

Finally, we consider parallel and perpendicular lines.

proff. halleck

i remember slope and y-intercept but today in class i was introduce to new things that included slopes and linear equations was confused a bit

Rebecca Kogan

Professor Halleck

Linear equations is pretty much easy when you know what to plug in into which equation. I found the videos on this page really helpful to help me further understand the topic.

Linear equations on a graph was giving me some difficulty, because i am not so well with graphs. That’s why math zone homework problems were harder even with guided help, though some i were able to figure out

I love slope and plotting line intercepts. Just another review. Thanks though.

John

Prof. Reitz

I never liked slopes and the formulas associated with them but maybe its because i didn’t understand them but these lessons and videos refresh and make it alot simpler to understand, doesn’t mean i like them now but i understand it better..

Pro. Halleck

It was okay, not into slopes but I somewhat understood the linear equations.

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