Answer
(a) 3
(b) -5
(c) $y=3x-5$
Work Step by Step
(a)
To find the midpoint between points $(x_1,y_1)$ and $(x_2,y_2)$, we use the midpoint formula:
$\displaystyle Midpoint=(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})$
We use the first two points in the table, $(-2,\ -11)$ and $(-1,\ -8)$:
$midpoint=slope=\frac{-8-(-11)}{-1-(-2)}$
$=\frac{3}{1}$
$=3$
(b) To find the $y$-intercept, we look when $x=0$ in the table. This occurs at $y=-5$. Thus:
y-intercept=$(0,-5)$
(c)
A line in slope-intercept has the form:
$y=mx+b$ ($m=slope$, $b=y-intercept$)
We plug in $m=3$ and $b=-5$:
$y=mx+b$
$y=3x-5$