Answer:
I'm guessing C
Step-by-step explanation:
I don't think this is the correct way to answer it. But I litterly rotated it in my brain and got 7.5....
Let the required point be (a,b)
The distance of (a,b) from (7,-2) is
= 
But this distance needs to be betweem 50 & 60
So

Squaring all sides
2500 < (a-7)² + (b+2)² < 3600
Let a = 7
So we have
2500 < (b+2)² <3600
b+2 < 60 or b+2 > -60 => b <58 or b > -62
Also
b+2 >50 or b + 2 < -50 => b >48 or B < -52
Let us take one value of b < 58 say b = 50
So now we have the point as (7, 50)
The other point is (7,-2)
Distance between them
= 
This is between 50 & 60
Hence one point which has a distance between 50 & 60 from the point (7,-2) is (7, 50)
Note that if

, then

, and so we can collapse the system of ODEs into a linear ODE:


which is a pretty standard linear ODE with constant coefficients. We have characteristic equation

so that the characteristic solution is

Now let's suppose the particular solution is

. Then

and so

Thus the general solution for

is

and you can find the solution

by simply differentiating

.
Answer:
the answer is that both x and y are acute