[tex]\displaystyle\bf\\a)~~\frac{21}{?}~lipseste~numitorul.\\\\b)~~\frac{15}{4}=3+\frac{3}{4}=3,75\\\\c)~~\frac{7}{8}=0,875\\\\d)~~\frac{1}{3}=0,(3)\\\\e)~~\frac{11}{9}=1+\frac{2}{9}=1,(2)\\\\f)~~\frac{25}{6}=4+\frac{1}{6}=4,1(6)\\\\g)~~\frac{13}{5}=2+\frac{3}{5}=2,6\\\\h)~~\frac{9}{11}=0,(81)[/tex]