$xb-a$

$\frac{1}{9}$ can be expressed as $\boxed{\frac{1}{14n-5}}$

$\frac{1}{25}$ can be expressed as $\boxed{\frac{1}{15n-5}}$

$\frac{1}{43}$ can be expressed as $\boxed{\frac{1}{16n-5}}$

$\frac{1}{63}$ can be expressed as $\boxed{\frac{1}{17n-5}}$

$\frac{1}{65}$ can be expressed as $\boxed{\frac{1}{14n-5}}$

$\frac{1}{85}$ can be expressed as $\boxed{\frac{1}{15n-5}}$

$\vdots$

$22{\equiv}4{\pmod{2}}$ and we have $\frac{1}{14n-5}$ , $\boxed{\frac{1}{15n-5}}$ , $\frac{1}{16n-5}$ , $\frac{1}{17n-5}$ $\dots$

Then $22^{nd}$ expressed as $\frac{1}{15n-5}$ .

$\frac{1}{22×15-5}{\implies}~{\frac{1}{330-5}}={\boxed{\frac{1}{325}}}$

Hence the answer as $\color{#3D99F6}{\boxed{{\frac{1}{325}}}}$