The slope of the line [tex] y=\frac{3}{5} x-1 [/tex] is [tex] m=\frac{3}{5} [/tex].
The line perpendicular to the above line has slope [tex] -\frac{1}{m} =-\frac{5}{3} [/tex]
Its equation is [tex] y=-\frac{5}{3} x+c[/tex]. Since this line passes through, [tex] (-9,4) [/tex],
[tex] 4=-\frac{5}{3} )(-9)+c\\ c=-11 [/tex]
Thus the equation of the line in slope intercept form is [tex] y=-\frac{5}{3} x-11 [/tex]