One more then I’ll stop being annoying just one more please literally one

Answer:
[tex]y = - 3x - 4[/tex]
Step-by-step explanation:
convert first equation to y=mx+b
[tex]7x - 21y = 39[/tex]
[tex]y = \frac{1}{3} x - \frac{13}{7} [/tex]
we know perpendicular lines have an opposite slope thus,
[tex]y = - 3x + b[/tex]
now plug in desired points, (-3,5)
[tex]5 = - 3( - 3) + b[/tex]
[tex]b = - 4[/tex]
thus,
[tex]y = - 3x - 4[/tex]