Respuesta :

You would multiply by 

[tex]\frac{9+\sqrt{14}}{9+\sqrt{14}}[/tex].

When you rationalize the denominator, you multiply by the conjugate of the denominator.  The conjugate is the same numbers and radicals, but with the sign of the radical switched.

Answer:

[tex]\frac{9+\sqrt{14}}{9+\sqrt{14}}[/tex]

Step-by-step explanation:

we have

[tex]\frac{5-\sqrt{7}}{9-\sqrt{14}}[/tex]

we know that

To rationalize the denominator, multiply by the conjugate of the denominator

so

[tex]\frac{5-\sqrt{7}}{9-\sqrt{14}}*\frac{9+\sqrt{14}}{9+\sqrt{14}}=\frac{(5-\sqrt{7})(9+\sqrt{14})}{9^{2}-14}\\ \\=\frac{(5-\sqrt{7})(9+\sqrt{14})}{67}[/tex]