[tex] \frac{575}{161} - \frac{45}{21} \\ \\ = \frac{575\times21}{161\times21} - \frac{45\times161}{21\times161} \\ \\ = \frac{12 \ 075}{3 \ 381} - \frac{7 \ 245}{3 \ 381} \\ \\ = \frac{12 \ 075-7 \ 245}{3 \ 381} \\ \\ = \frac{4 \ 830}{3 \ 381} \\ \\ = \frac{483 \times10}{483\times7} \\ \\\boxed{= \frac{10}{7} }[/tex]
