Answer:
a.

b.

Explanation:
Given
A(-8,7) and B(6,-9).
Solving (a):
Determine the Midpoint M;
This is calculated as follows;

Where


Substitute these values in the formula



Hence; the midpoint is (-1,-1)
Solving (a):
Here, we have
C = (2,7)
M; Midpoint = (-1,-1)
Required: Determine D
This is calculated as follows;

Where


Substitute these values in the formula

Solving for x2

Multiply both sides by 2

Subtract 2 from both sides


Solving for y2

Multiply both sides by 2

Subtract 7 from both sides


Hence, the coordinates of D is
