Ответ:

  1. \(\frac{9}{11}+\frac{3}{5}:\frac{11}{40}=\frac{9}{11}+\frac{3}{5}\cdot\frac{40}{11}=\frac{9}{11}+\frac{24}{11}=3\).
  2. \(2\frac{1}{16}:\frac{3}{4}+\frac{1}{4}=\frac{33}{16}\cdot\frac{4}{3}+\frac{1}{4}=\frac{11}{4}+\frac{1}{4}=3\).
  3. \(1-\frac{3}{8}\cdot3\frac{1}{5}=1-\frac{3}{8}\cdot\frac{16}{5}=1-\frac{6}{5}=-\frac{1}{5}\).
  4. \(-1,75\cdot(-8,7+6,3)=-1,75\cdot(-2,4)=4,2\).
  5. \(-4,5+6,24:1,6=-4,5+3,9=-0,6\).
  6. \(\frac{17,1-2,8}{2,2}=\frac{14,3}{2,2}=6,5\).

Ответ: 1) 3; 2) 3; 3) \(-\frac{1}{5}\); 4) 4,2; 5) −0,6; 6) 6,5.