Answer:
y = - 2x
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Given
2y = x - 3 ( divide the terms by 2 )
y =
x -
← in slope- intercept form
with slope m = 
Given a line with slope m then the slope of a line perpendicular to it is
= -
= -
= - 2 , then
y = - 2x + c ← is the partial equation
To find c, substitute (- 1, 2) into the partial equation
2 = 2 + c ⇒ c = 2 - 2 = 0
y = - 2x ← equation of the perpendicular line