ANSWER
2n + 5t - 3u
EXPLANATION
Given that;
[tex]\text{ 2n - \lparen-5t + 3u\rparen}[/tex][tex]\begin{gathered} \text{ 2n -}\times\text{\lparen-5t\rparen - }\times\text{ \lparen+3u\rparen} \\ \text{ recall,} \\ \text{ - }\times\text{ - = +} \\ \text{ - }\times\text{ + = -} \\ \text{ so,} \\ \text{ 2n + 5t - 3u} \end{gathered}[/tex]