Example 1:
Sentence: answer is } C=2. \]
Answer: C=2

Example 2:
Sentence: answer is } C = \frac{1}{\sqrt{2}}. \]
Answer: C = \frac{1}{\sqrt{2}}

Example 3:
Sentence: answer is $\boxed{C=2}$.
Answer: C=2

Example 4:
Sentence: answer is $ C = 3 $.
Answer: C=3
