Let \( x \) and \( y \) be real numbers such that \( 50\!\left(\dfrac{2x}{1+3i} - \dfrac{y}{1-2i}\right) = 31 + 17i \), \( i = \sqrt{-1} \). Then the value of \( 10(x-3y) \) is:
\( 20 \)
\( 31 \)
\( 35 \)
\( 75 \)