$a)\text{Dla}x=-2,\frac{4\cdot {\left(-2\right)}^4-24}{-{\left(-2\right)}^2}=\frac{4\cdot 16-24}{-4}=\frac{64-24}{-4}=\frac{40}{-4}=-10$

$b)\text{Dla}x=-2,\frac{2\cdot \left(-2\right)+18}{3\cdot {\left(-2\right)}^2-5}+\frac{2}{{\left(-2\right)}^3}=\frac{-4+18}{3\cdot 4-5}+\frac{2}{-8}=\frac{14}{7}-\frac{1}{4}=2-\frac{1}{4}=\frac{7}{4}=1\frac{3}{4}$  

$c)\text{Dla}x=-2,\frac{-{\left(-2\right)}^3+4\cdot {\left(-2\right)}^2}{3\cdot \left(-2\right)}=\frac{-\left(-8\right)+4\cdot 4}{-6}=\frac{8+16}{-6}=\frac{24}{-6}=-4$