Slope: the slant of a line -- the ratio of the change in the y-axis to the change in the x-axis between two points on a line
PROPERTY OF STRAIGHT LINES: SLOPE REMAINS CONSTANT
**Any two points will have the same slope.**
Some people like to think of slope as:
Others think of it as:
y2 - y1
x2 - x1
in which y2 and y1 are the two y coordinates and x2 and x1 are the two x coordinates. Remember: y2 and x2 must be from the same point, as x1 and y1 must be (there is point 1 and point 2).
Let us take the equation we had...x + y = 4
The graph was:
Let's pick 2 points from this line...(1,3) and (4,0)
x1 = 1, x2 = 4
y1 = 3, y2 = 0
x2 - x1
4 - 1
= = = -1
y2 - y1 0 - 3 -3
** "m" denotes slope....so in this equation, m = -1
**Often slope IS A FRACTION...this turned out to be an integer.**
AS A RULE OF THUMB: Any line going up on the left will have a negative slope...any line going up on the right will have a positive slope.
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