Geometry

The correct answer is C.23.

 

1. Since  is the midpoint of , we know that  (by the definition of a midpoint, which divides a line segment into two equal parts), so .

Given that  and , we can set up the equation:

.

 

2. Expand the left side of the equation:

Using the distributive property , where , , and , we get .

 

3. Solve for :

Subtract  from both sides of the equation: