Tính. ( frac{1}{4} ) + ( frac{1}{{16}} ) = ……………………………… ( frac{{34}}{{45}} ) – ( frac{1}{3} ) = ……………………………… ( frac{8}{{35}} ) × ( frac{7}{{64}} ) = ……………………………… ( frac{5}{{18}} ) : ( frac{{20}}{9} )...

( frac{1}{4} ) + ( frac{1}{{16}} ) = ( frac{4}{{16}} ) + ( frac{1}{{16}} ) = ( frac{5}{{16}} ) ( frac{{34}}{{45}} ) – ( frac{1}{3} ) = ( frac{{34}}{{45}} ) – ( frac{{15}}{{45}} ) = ( frac{{19}}{{45}} ) ( frac{8}{{35}} ) × ( frac{7}{{64}} ) = ( frac{1}{{40}} ) ( frac{5}{{18}} ) : ( frac{{20}}{9} ) = ( frac{5}{{18}} ) × ( frac{9}{{20}} ) = ( frac{1}{8} )