hello!
Perpendicular lines have slopes that are opposite reciprocals.
This means we take a number, flop it over, and change its sign.
Here we have the number:-
[tex]\boxed{\frac{7}{3}}[/tex]
Flop it over:-
[tex]\boxed{\frac{3}{7} }\longleftarrow\sf{the~numerator~and~denominator~switch~places}[/tex]
Change its sign:-
[tex]\boxed{-\frac{3}{7}}[/tex]
Hence, the slope of line e is:-
[tex]\bigstar{\boxed{\pmb{Slope=-\frac{3}{7}}}}[/tex]
note:-
Hope everything is clear; if you need any explanation/clarification, kindly let me know, and I will comment and/or edit my answer :)
