Ответ:

  1. а) \(4-\frac13\cdot3.6=4-1.2=2.8\).
  2. б) \(\frac{27}{35}:\left(-\frac{54}{7}\right)-2.4=\frac{27}{35}\cdot\left(-\frac{7}{54}\right)-2.4=-0.1-2.4=-2.5\).
  3. в) \(\frac{5.2+6.2}{1.2}=\frac{11.4}{1.2}=9.5\).
  4. г) \(\left(\frac58+3\frac23\right)\cdot2.4=\left(\frac{15}{24}+\frac{88}{24}\right)\cdot\frac{12}{5}=\frac{103}{24}\cdot\frac{12}{5}=\frac{103}{10}=10.3\).

Ответ: а) 2,8; б) −2,5; в) 9,5; г) 10,3.