$\displaystyle \frac{300}{900}$\displaystyle \frac{300}{900}

$\displaystyle \frac{300}{900-1}$\displaystyle \frac{300}{900-1}

$\displaystyle \frac{300}{900+1}$\displaystyle \frac{300}{900+1}

$\displaystyle \frac{300-1}{900}$\displaystyle \frac{300-1}{900}