A problem begins with Nemeth mode already open. The problem ends with punctuation. Nemeth needs to be closed because the following problem begins with copious words. There is no room for the both the punctuation and closing at the end of the line. Where does the closing Nemeth indicator go?
An example with three possible choices is attached. Of course, this has come up repeatedly for me, and not all problems actually have all three choices due to the length of the math expression and such.
A Nemeth Code terminator followed by punctuation may begin a line if they will not fit on the preceding line (or if fitting them would require dividing a math expression). Punctuation that follows a Nemeth Code terminator may not begin a line by itself.
I’m afraid your file did not attach. Could you attach a BRF instead of a DXB?
I've looked at your attachment, and your third option is the correct one. This is because it keeps the math expression altogether on one braille line and allows the Nemeth Code terminator to be placed on a line with material preceding it. In other words, there is a preference for keeping the terminator on a line with the math expression, and there is no rule or preference for keeping the word "Solve:" with the math expression that follows it.