Answer
(a) $y=-\frac{1}{3}x-3$
(b) $slope=m=-\frac{1}{3}$
(c) $y-intercept=b=-3$; point $(0,-3)$
(d) See graph.
Work Step by Step
(a)
A line in slope-intercept form has the equation:
$y=mx+b$ ($m=slope$, $b=y-intercept$)
We put the equation into slope-intercept form:
$x+3y=-9$
$3y=-x-9$
$y=-\frac{1}{3}x-3$
(b) We see that $slope=m=-\frac{1}{3}$
(c) We see that $y-intercept=b=-3$; point $(0,-3)$
(d) See graph.