we have that
the equation for the line that crosses the point (2,-5) and is perpendicular to the line y=2/3x+4
two lines are perpendicular if m1*m2=-1
y=2/3x+4-----------> m1=2/3
then
m2=-3/2
the equation of a line is
point (2,-5) and m2=-3/2---> -1.5
y-y1=m*(x-x1)
y+5=(-1.5)*(x-2)-------> y=-1.5x+3-5--------> y=-1.5x-2
the answer is
y=-1.5x-2
see the attached figure