+128474 Let's find M thusy
Note that there are 5 equal sements in PQ.....M is 2/5 of the way between these....so we have..
[ -9 + (11 - -9)(2/5) , 7 + (12 - 7) (2/5) ] =
[ -9 + (20)(2/5) , + 7 + (5)(2/5) ]=
[ -9 + 8 , 7 + 2 ] =
(-1, 9) = M
The slope of PQ is [ 12 - 7 ] / [ 11 - - 9 ] = 5/20 = 1/4
So...the slope of the perpendicular line through M = -4/1 = -4
So...the equation of the line L is
y = -4 (x - -1) + 9
y = -4( x + 1) + 9
y = -4x - 4 + 9
y = -4x + 5
Here's a graph : https://www.desmos.com/calculator/axxvuzl6js
