Greetings! Lets solve this shall we ?
So, we must find the value of k using the given information. We have to find the equation of a line with the given points (-4,-9) and (2,-3) first before we can find the value of k. Now, we find the slope such that
m = (-3-(-9)) / (2-(-4)) = 6 / 6 = 1. Then we yields the point-slope formula to find the equation of a line such that
y - y1 = m(x - x1)
y - (-9) = (1)(x - (-4))
y + 9 = x + 4
y = x - 5
The other given points with k involved has to give a line parallel to y = x - 5 where the slope must be the same m = 1 such that
m = [(3-k) - (-4)] / [5 - (2k+1)] = 1
(7-k) / (4-2k) = 1............Then we cross multiply to get
7 - k = 4 - 2k............Then we solve for k by first adding 2k to the other side such that
7 + k = 4.............Then subtract 7 to the other side such that
k = -3
I hope this helped!