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