y = -2x - 5.....slope here is -2. A perpendicular line will have a negative reciprocal slope. All that means is " flip " the slope and change the sign. So the slope we will need is : 1/2. See how I flipped the slope of -2/1 and changed it to -1/2.....now I change the sign making our new slope be 1/2.
y = mx + b
slope(m) = 1/2
(-1,-2).....x = -1 and y = -2
now sub and find b, the y int
-2 = 1/2(-1) + b
-2 = -1/2 + b
-2 + 1/2 = b
-4/2 + 1/2 = b
-3/2 = b
so ur perpendicular line is : y = 1/2x - 3/2
