Arthur D. answered 01/11/17
Tutor
4.9
(274)
Forty Year Educator: Classroom, Summer School, Substitute, Tutor
triangle PQR with midpoints (-2,3), (5,-1), and (-4,-7)
P=(a,b), Q=(c,d), R=(e,f)
working with the x-coordinates first...
segment PQ:
(a+c)/2=-2
segment QR:
(c+e)/2=5
segment RP:
(e+a)/2=-4
a+c=-4
c+e=10
e+a=-8 -------->e=-a-8
a+c=-4
c+(-a-8)=10
c-a=18
c+a=-4
2c=14
c=7
a=-11
e=3
now work with the y-coordinates in the same manner
(b+d)/2=3
(d+f)/2=-1
(f+b)/2=-7
b+d=6
d+f=-2------>f=-2-d
f+b=-14
-2-d+b=-14
-d+b=-12
d+b=6
2b=-6
b=-3
d=9
f=-11
P=(-11,-3), Q=(7,9), R=(3<-11)

Arthur D.
01/11/17