Can you please solve this I don't understand perpendicular lines

Answer:
The equation of the perpendicular line 't' is 3x+y =0
Point slope form y = mx +C
y = - 3x
Step-by-step explanation:
Step(i):-
Given equation s = [tex]\frac{1}{3}x +10[/tex] and given point (1,-3)
The equation of the perpendicular line
[tex]y =\frac{x+30}{3}[/tex]
⇒ 3 y = x+30
⇒ x - 3y +30 =0
Step(ii):-
The perpendicular line of the given straight line 's'
b x -ay +k=0
⇒ -3x -y +k=0
This line is passing through the point (1,-3)
-3(1)-(-3)+k=0
k =0
The equation of the perpendicular line -3x-y =0
Final answer:-
The equation of the perpendicular line 3x+y =0
Point slope form y = mx +C
y = - 3x