Answer
$\dfrac{1}{2}$;
$-2$
Work Step by Step
RECALL:
(i) The linear equation $y=mx+b$ has $m$=the slope and $b$=the y-intercept.
(ii) Perpendicular lines have opposite reciporcal slopes.
The given equation has $m=\frac{1}{2}$, so the slope of the line is $\frac{1}{2}$.
The slope of a line that is perpendicular to this line has a slope of the opposite reciprocal of 1/2. which is $-2$.