[tex]2 \frac{2}{5} * \frac{3}{8} : \frac{9}{10} +2 \frac{1}{7} :4 \frac{1}{2} *5 \frac{1}{4} =?[/tex]

спс

1) 2 ( 2/5 ) * ( 3/8 ) : ( 9/10 ) = ( 12/5 ) * ( 3/8 ) * ( 10/9 ) = 360/360 = 1 2) 2 ( 1/7 ) : 4 ( 1/2 ) * 5 ( 1/4 ) = (15/7 ) * (  2/9  ) * ( 21/4 ) = 630/252 = 2,53) 1 + 2,5 = 3,5 ОТВЕТ 3,5