[tex]\displaystyle 1)\frac{7}{34}*\frac{17}{21}=\frac{1}{2}*\frac{1}{3}=\frac{1}{6}\\ \\2)6\frac{1}{9}*1\frac{37}{44}=\frac{55}{9}*\frac{81}{44}=5*\frac{9}{4}=\frac{45}{4}=11\frac{1}{4}=11,25\\ \\3) 9\frac{2}{7}*\frac{19}{26}*1\frac{2}{19}=\frac{65}{7}*\frac{19}{26}*\frac{21}{19}=5*\frac{1}{2}*3=\frac{15}{2}=7\frac{1}{2}=7,5[/tex]