So what you have is this:
y = -65x + 1000
this is a form of
,
where
is the slope and 
is the y-intercept of the linear relationship.
so, -65 is and 1000 is the
It should be a piece of cake from there :D
y = -65x + 1000
this is a form of
where
so, -65 is
It should be a piece of cake from there :D