Answer
(a) See the image above
(b)The slope represents rate at which number of spaces ($y$) changes with respect to the charge per space.
$y$-intercept $(0, 200)$ represents amount of spaces she can rent if she charges no money. That is $200$.
$x$-intercept $(50, 0)$ represents amount of money she charges for each space ($\$50$) when there is no space rented.
Work Step by Step
(a) We can simply input $x$ values to the equation ($2$ values are enough) and graph a line through these points. But note, we have to consider only positive values of both $x$ and $y$.
See the image above.
(b) $y=-4x+200$
The slope represents rate at which number of spaces ($y$) changes with respect to the charge per space.
$y$-intercept $(0, 200)$ represents amount of spaces she can rent if she charges no money. That is $200$.
$x$-intercept $(50, 0)$ represents amount of money she charges for each space ($\$50$) when there is no space rented.
