Let's begin by listing out the information given to us:
We start out by observing that Triangles MKR & ACD are similar or proportional

We will solve for the missing side by using the similar triangle theorem. This is shown below:~
Answer: C. x-2
Step-by-step explanation:
We have the following expression:

Factoring in the numerator:

Factoring again in the numerator with common factor
:

Simplifying:

Hence, the correct option is C. x-2
(1) Repetition allowed : There are 4 choices for both positions, so 4 × 4 = 16 2-digit numbers can be formed. (2) Repetition not allowed : There are 4 options for tens position, and three options for ones position. Therefore, 4 × 3 = 12 2-digit numbers can be formed.