To simplify \( 37x + 27x \), you can combine the like terms:
\[ 37x + 27x = (37 + 27)x = 64x \]
None of the provided responses match \( 64x \). If "57x" is meant as "64x" due to copying error, then 64x would be the simplified answer.
However, if I had to choose the closest option:
- 57x is incorrect.
The correct answer after simplification is \( 64x \).