Graphing Linear Equations

Slope of Lines:

Slope - used to determine how fast a graph is increasing or decreasing on a specific equation.

Find the slope of an equation that goes through the points (4,7) (3,8)

A simple equation allows us to do this.

(Y2-Y1)/(X2-X1) » (8-7)/(3-4) » 1/-1 = -1 

The graph is always decreasing at a rate of -1

Remember: IF Y=number then the slope is zero

                     IF X=number then there is no slope

To find an equation from points:

You must know the slope (M),

Y-intercept - The place where the line crosses the y-axis, or when y=0

M=-3 (0, -5).  Answer is  Y= -3x+5

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