Ответ:

1) \(\dfrac{6.9-1.5}{2.4}=\dfrac{5.4}{2.4}=2.25\).

2) \(\left(\dfrac{19}{8}+\dfrac{11}{12}\right):\dfrac{5}{48}=\left(\dfrac{57}{24}+\dfrac{22}{24}\right)\cdot\dfrac{48}{5}=\dfrac{79}{24}\cdot\dfrac{48}{5}=\dfrac{158}{5}=31.6\).

3) \(13\dfrac{3}{4}=13.75\), а \(1\dfrac{1}{3}\cdot2.01=\dfrac{4}{3}\cdot2.01=2.68\). Поэтому \(13.75+(3.25-2.68)=13.75+0.57=14.32\).

Ответ: 1) 2,25; 2) 31,6; 3) 14,32.