Answer
(a) $y=4$
(b) $y=4$
Work Step by Step
(a) The line $x=-3$ is horizontal (because it has the form $x=constant$) and thus a perpendicular line would be vertical (with the form $y=constant$). Since the line must pass through the point $(8,4)$, we know that the form of the equation must be:
$y=4$
(b) $y=4$ is in standard form.