We need to multiply by the conjugate of the denominator to rationalize all square roots.
$$ \frac{2-i}{-3+i} $$
$$ \frac{2-i}{-3+i}\cdot \frac{-3-i}{-3-i} $$
$$ = \frac{(2-i)(-3-i)}{(-3+i)(-3-i)} $$
$$ = \frac{-6+3i-2i+i^2}{9-i^2} $$
$$ = \frac{-6+i+(-1)}{9-(-1)} $$
$$ = \frac{-7+i}{10} $$
$$ = \boxed{-\frac{7}{10}+\frac{1}{10}i} $$