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Slope of Line
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Find the slope of the lines on the following graphs.

When reading left to right a positive sloped line will rise or go uphill

When reading left to right a negative sloped line will decline or go downhill

A horizontal line has a slope of 0 because a horizontal line has no vertical change

Vertical line has no slope because the horizontal change equals 0

Parallel lines are two lines in a plane that never intersect. Parallel lines have the same slope.

Perpendicular are two lines that intersect and create right 90 degree angles and their slopes negative reciprocals. For example the negative reciprocal of 1 /2 = - 2/1

What is the slope of a line? The slope is a measure of how the line angles away from the horizontal.One can also think of slope as the "slant" of a line The slope of a line is a rate change and the letter m is used to represent slope. The slope of a line never changes, therefore you can find the slope of a line without graphing if you know any two points on a line, or any two solutions of a linear equation.

The formula for slope of a line is
In an algebraic relationship slope measures the rate of change. Because linear equations have a constant rate of change they result in a straight line on a graph.

Let's look at an example question.
What is the slope of a line passing through the points  (5,4) and (9,2) ?

Line n has a rise of -1 and a run of 4 so...
-1/4 =  so the slope of line N =  negative 1/4

Line M has a rise of 3 and a run of 1 so ...
3/1 = +3 so line m has a slope of positive 3
Video goes over the answer
M
N

## Slope of a Line

Video Answer of Slope passing through (5,4) and ( 9,2)