I’m okay stressed out cuz homework haha
ANSWER:
d. (−4, 10)
STEP-BY-STEP EXPLANATION:
The midpoint has the following definition:

We can calculate point B, using the following equations obtained taking into account the above:

The correct answer is: d. (−4, 10)
Answer:
So, this triangle PQR can be broken into two right triangles, PNQ and PNR, with legs PQ = 39, PN =15, and QN = ? and PR = 17, PN = 15, and NR =? respectively.
Let's solve for what is easier first:
Since we know that 5-15-17 is a Pythagorean triplet, we can infer that NR is 5....like I said earlier, it is a right triangle, so this guess holds true.
Here comes the interesting part:
Now, we have one part of QR, which is QN.
The other part can be solved by using the Pythagorean theorem.
It is (39^2-15^2)^(1/2)..which gives you 36, the square root of 1296, which happens to be the difference between the squares of 15 and 39.
SO, QR = QN + NR
5+36 = 41
QR = 41.
Hope this helps!
notice that, if Q is the midpoint of PR, that simply means that PQ = QR = 43.
![\bf \boxed{P}\underset{\leftarrow 9x-31 \to }{\stackrel{\stackrel{\downarrow }{43}}{\rule[0.35em]{10em}{0.25pt}}Q\stackrel{43}{\rule[0.35em]{10em}{0.25pt}}}\boxed{R} \\\\\\ 9x-31=43+43\implies 9x-31=86\implies 9x=117 \\\\\\ x=\cfrac{117}{9}\implies x=13](https://tex.z-dn.net/?f=%5Cbf%20%5Cboxed%7BP%7D%5Cunderset%7B%5Cleftarrow%209x-31%20%5Cto%20%7D%7B%5Cstackrel%7B%5Cstackrel%7B%5Cdownarrow%20%7D%7B43%7D%7D%7B%5Crule%5B0.35em%5D%7B10em%7D%7B0.25pt%7D%7DQ%5Cstackrel%7B43%7D%7B%5Crule%5B0.35em%5D%7B10em%7D%7B0.25pt%7D%7D%7D%5Cboxed%7BR%7D%0A%5C%5C%5C%5C%5C%5C%0A9x-31%3D43%2B43%5Cimplies%209x-31%3D86%5Cimplies%209x%3D117%0A%5C%5C%5C%5C%5C%5C%0Ax%3D%5Ccfrac%7B117%7D%7B9%7D%5Cimplies%20x%3D13)