Assuming your plus sign means divide: [tex] \frac{4}{10} / \frac{5}{10} [/tex] becomes [tex]\frac{4}{10} * \frac{8}{5} [/tex] you flip the second fraction and multiply. To multiply you multiply across the bottom and then across the top. [tex] \frac{4}{10} * \frac{8}{5} = \frac{32}{50} or \frac{16}{25} or .64[/tex]
