When two lines are perpendicular, the slopes of the lines m1 and m2 are related such that
m1m2 = -1
from the given equation comparing with tyhe general form of the equation of a line (y = mx + c)
m1 = 4/3
The slope of the perpendicular line is -3/4
The equation of the line
y- -1 = -3/4(x - -4)
y + 1 = -3/4(x + 4)
y + 1 = -3x/4 - 3
Subtract 1 from both sides
y + 1 - 1 = -3x/4 - 3 - 1
y = -3x/4 - 3 - 1
y = -3x/4 - 4
This is the standard form of the equation