Answer
The equation is $y=-0.5x+9.5$
Work Step by Step
The slope of a perpendicular line is the negative inverse: $-\frac{a}{b} \rightarrow \frac{b}{a}$
So, the slope perpendicular to the one of $y=2x+1$ is -0.5
Now that we have the slope and a point, we can find the equation of the perpendicular line by first finding its y-intercept (b) with y=mx+b (which is the slope-intercept form):
$5=-0.5(3)+b$
$5=-4.5+b$
$5+4.5=-4.5+b+4.5$
$b=9.5$
So, the equation of the perpendicular line is $y=-0.5x+9.5$
