Answer:
x = 5
Step-by-step explanation:
The opposite sides of a parallelogram must be parallel to each other, and this is shown by the equivalent opposite interior angles on each side of the bisector.
Since the opposite sides of a parallelogram are parallel, they must be of equal length (this is one of the fundamental properties of a parallelogram).
Therefore, we can set (18x - 5) and (16x + 5) equal to each other in an equation and solve for x.
Subtract 16x from both sides.
Add 5 to both sides.
Divide both sides by 2.
The value of 5 for x must make ABCD a parallelogram.
