Answer:
Step-by-step explanation:
If S is the midpoint of R and S and the coordinate R(-9, 4) and S(2, -1), we are to find T.
Usimg the midpoint formula;

Given
, to get the other coordinate T (x2, y2), we will use the formula above as shown;

Similarly to get y2;
Y = y1+y2/6
-1 = 4+y2/2
cross multiply
-1*2 = 4+y2
-2 = 4+y2
y2 = -2-4
y2 = -6
Hence the coordinate T is (13, -6)