Equations as lines!

Slope intercept form

Graph these equations:

y = x

y = 2x

y = 5x

and then 

y = -x

y = -3x

compare...the coefficient is the slope of the line (rise over run)

Graph y = x

then graph

y = x +3

y = x -4

y = x +5

compare!

then graph 

y = 2x 

y = 2x + 4

y = 2x - 3

the constant is the y-intercept...the place where the line crosses the y-axis!