Simplify each expression. 28. \( \left(8 b^{\frac{2}{3}} \cdot 9 t^{\frac{1}{5}}\right)\left(8 b^{\frac{5}{3}} \cdot 9 t^{\frac{3}{5}}\right) \)

To simplify the expression \( \left(8 b^{\frac{2}{3}} \cdot 9 t^{\frac{1}{5}}\right)\left(8 b^{\frac{5}{3}} \cdot 9 t^{\frac{3}{5}}\right) \), we can first rewrite it by multiplying the coefficients and combining the like bases: 1. Multiply the coefficients: \( 8 \cdot 8 = 64 \) and \( 9 \cdot 9 = 81 \). Therefore, \( 64 \cdot 81 = 5184 \). 2. For the \( b \) terms, we add the exponents: \[ b^{\frac{2}{3}} \cdot b^{\frac{5}{3}} = b^{\frac{2}{3} + \frac{5}{3}} = b^{\frac{7}{3}}. \] 3. For the \( t \) terms, we also add the exponents: \[ t^{\frac{1}{5}} \cdot t^{\frac{3}{5}} = t^{\frac{1}{5} + \frac{3}{5}} = t^{\frac{4}{5}}. \] Putting it all together, the simplified expression is: \[ 5184 b^{\frac{7}{3}} t^{\frac{4}{5}}. \]