to move a funciton up z units, add z to the whole function
y=x+5
compared to
y=x+9
we added 4 to the whole function
it is a vertical shift up 4 units
we could also do
to move a graph to the right c units, minus c from every x
we added 4 to every x aka minused -4 so
we horizontal shift -4 to the right or horizontal shift 4 to the left
vertical shift 4 units up or horizontal shift 4 units to left (same result, 2 ways of saying it)