Question 358820: Trying to understand graphs of linear equations first time doing this. Slope: -1, y-intercept:2.
Answer by neatmath(302)   (Show Source):
You can put this solution on YOUR website! Okay, first, the y-intercept.
The y-intercept is just the point on a graph of an equation where the graph crosses the y-axis.
The y-intercept can be labeled as just a number y, or it is in the form (0,y) where y is some number.
The y-intercept will always be (0,y) and as you can imagine, the x-intercept is similar.
It is the point where the graph crosses the x-axis and is always labeled as a number x, or as the point (x,0).
A graph of an equation can have many x-intercepts and y-intercepts.
The good thing about a line is that it can have only one y-intercept and one x-intercept, unless it is a vertical line (x=0) or horizontal line (y=0).
As far as the slope goes, that is just a number m, which gives you the "slant" of the line (or curve) that you have graphed.
You can always calculate the slope of a line using two points on the line in this formula:
 where the points are (x1,y1) and (x2,y2)
The slope is also known as RISE over RUN or 
When the slope m is a positive number, the line increases or goes upwards as it goes from left to right.
Conversely, when the slope is a negative number, the line decreases or goes downward as it goes from left to right.
The slope of a horizontal line, such as y=4, is always m=0
The slope of a vertical line, such as x=2, is always undefined.
There are many different uses for the slope of a line (or curve), but for some early algebraic techniques, it is used mostly for graphing a line.
You will find many more uses for the slope of a line (or portion of a curve) when you discover Calculus!
I hope this helps!
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