The given equation is y=-2x-4.
The slope of that line is -2.
A perpendicular line has a slope, that is the negative reciprocal of the given slope.
The negative reciprocal of - 2 is 1/2
Now using the given pint solve for the y-intercept:
0.5 = 0.5*-0.5 +b
0.5 = -0.25 +b
b = 0.5 + 0.25 = 0.75
The new equation is: y = 0.5x +0.75