\(( \frac{3}{4} )^2= \frac{3}{4} * \frac{3}{4}\) and multiply across. Then you have \(\frac{9}{16} - \frac{1}{10}\). You want each fraction to have the same denominator so \(\frac{9}{16} * \frac{10}{10}\) and \(\frac{1}{10} * \frac{16}{16}\). This results in \(\frac{90}{160} - \frac{16}{160} = \frac{74}{160} = \frac{37}{80}\). 37 is a prime number so you can't reduce any further.
