Question 669706
Starting with the line y = 2x-3
...
the slope is 2
...
the slope of the perpendicular line is {{{-1/2}}}
...
Using the coordinate (4, 5) and the determined slope, the linear equation is:
{{{5 = (-1/2)4 + b}}}
b = 5 + 2 = 7
...
y = {{{-1/2}}}x + 7
...
Given the coordinates (2, k)
{{{k = (-1/2)(2) + 7 = -1 + 7 = highlight_green(6)}}}

.....................
Delighted to help.
-Reading Boosters
Wanting for others what we want for ourselves.
www.MyHomeworkAnswers.com