Answer
$a)$ $y=2x+6$
$b)$ $2x-y+6=0$
$c)$ Graph below
Work Step by Step
The line that has slope $2$ and $y$-intercept $6$
$a)$
The slope-intercept form of the equation of a line is $y=mx+b$, where $m$ is the slope of the line and $b$ is its $y$-intercept.
Both the slope and the $y$-intercept are given.
Substitute them into the slope-intercept form of the equation of a line formula:
$y=2x+6$
$b)$
To write the equation in general form, just take $y$ to the right side of the equation:
$y=2x+6$
$0=2x-y+6$
$2x-y+6=0$
$c)$ Graph below
