Answer:
d. 19√2 -29
Step-by-step explanation:
Multiply numerator and denominator by the conjugate of the denominator.
[tex]\dfrac{9-10\sqrt{2}}{\sqrt{2}+1}=\dfrac{(9-10\sqrt{2})(\sqrt{2}-1)}{(\sqrt{2}+1)(\sqrt{2}-1)}\\\\=\dfrac{9\sqrt{2}-9-10\cdot2+10\sqrt{2}}{2-1}=\boxed{19\sqrt{2}-29}[/tex]
