a)
[tex]\dfrac{10-4\sqrt2}{2}=\dfrac{2(5-2\sqrt2)}{2}=\huge\boxed{5-2\sqrt2}}[/tex]
b)
[tex]\dfrac{-3\pi+9}{-3}=\dfrac{-3(\pi-3)}{-3}=\huge\boxed{\pi-3}[/tex]
