<image> As shown in the figure, there is a piece of rectangular land by the pond with a length of 18 meters and a width of 10 meters. Now, a path with the width of x meters on three sides is left, leaving the rectangular part in the middle as a vegetable garden. Express the following in algebraic form:
$$(1)$$ The length of the vegetable garden $$a=$$ ______ meters, the width of the vegetable garden $$b=$$ ______ meters;
$$(2)$$ The area of the vegetable garden $$S=$$ ______ square meters;
$$(3)$$ Find the area of the vegetable garden when $$x=1$$ meter.