In order to calculate the subtraction of the vectors, we can do the following steps:
[tex]\begin{gathered} u-v\\ \\ =(-10i+3j)-(-3i-7j)\\ \\ =-10i+3j+3i+7j\\ \\ =(-10i+3i)+(3j+7j)\\ \\ =-7i+10j \end{gathered}[/tex]Therefore the correct option is the first one.