Answer
$y=-0.5x-1.5$
Work Step by Step
The slope of the line can be found as two perpendicular lines' slopes' product equals to $-1$.
Therefore the product of the slope of the line $y=2x-3$ and the one we are trying to find equals to $-1$.
In this form the coefficient of $x$ gives the slope.
As $m_1=2$ , then
$2\times m_2=-1$
$m_2=-0.5$, this is the slope of the line we are trying to find.
If we have the slope and a point on the graph $(1,-2)$ we can use the point-slope formula to calculate the equation of the line:
$y-y_1=m(x-x_1)$
which translates to $y-(-2)=-0.5(x-1)$
The equation of the line is therefore: $y+2=-0.5x+0.5$
or $y=-0.5x-1.5$