Answer:
y = -1/2x -3
Step-by-step explanation:
The line perpendicular to one with a slope of 2 will have a slope that is the negative reciprocal of 2, that is, -1/2. The given point is the y-intercept of the required line, so we can write its equation directly in slope-intercept form:
y = mx + b
where m is the slope (-1/2), and b is the y-intercept (-3). Your line is ...
y = -1/2x -3
