Mentally, they are numbers in which you can do mental math with since they are whole numbers
The answer is (-6, 5) for K.
In order to find this, we must first note that to find a midpoint we need to take the average of the endpoints. To do this we add them together and then divide by 2. So, using that, we can write a formula and solve for each part of the k coordinates. We'll start with just x values.
(Kx + Lx)/2 = Mx
(Kx + 8)/2 = 1
Kx + 8 = 2
Kx = -6
And now we do the same thing for y values
(Ky + Ly)/2 = My
(Ky + -7)/2 = -1
Ky + -7 = -2
Ky = 5
This gives us the final point of (-6, 5)
You just need to divide the yearly salary by the number of weeks per year to get
48000/52 weeks=923 is the amount that she should spend no more than one week's pay which is the maximum amount per month that she can spend on rent.