The point slope form formula is as follows:
[tex]y-y_{1}=m(x-x_{1})[/tex]
(1,9) can be used to replace [tex]y_{1}[/tex] and [tex]x_{1}[/tex].
Since the slope is -2, we can use that to replace m.
[tex]y-9=-2(x-1)[/tex]
If you want this to be simplified, we can use the Distributive Property:
[tex]y-9=-2x+2[/tex]
And we can use the Addition Property of Equality to convert it to Slope intercept form:
[tex]y=-2x+11[/tex]
Hope this helps! :^)
