$A= \dfrac{-5}{11} . \dfrac{7}{15} . \dfrac{11}{-5} . (-30)$
$A = \dfrac{-5.7.11.(-30)}{11.15.(-5).1}$
$A = \dfrac{1.7.1.(-2)}{1.1.1.1}$
$A = -14$
$B = \dfrac{-1}{6} . \dfrac{-15}{19} . \dfrac{38}{45}$
$B = \dfrac{-1.(-15).38}{6.19.45}$
$B = \dfrac{15.38}{6.19.45}$
$B = \dfrac{1.2}{6.1.3}$
$B = \dfrac{1}{9}$
$C = (2\dfrac{2}{15} . \dfrac{3}{32} . \dfrac{9}{17}) : \dfrac{-3}{17}$
$C = (\dfrac{32}{15} . \dfrac{3}{32} . \dfrac{9}{17}) : \dfrac{-3}{17}$
$C = \dfrac{32.3.9}{15.32.17} : \dfrac{-3}{17}$
$C = \dfrac{32.3.9.17}{15.32.17.(-3)}$
$C = \dfrac{-3}{5}$
$D= \dfrac{8^{10} + 4^{10}}{8^4 + 4^{11}}$
$D = \dfrac{(2^3)^{10} + (2^2)^{10}}{(2^3)^4 + (2^2)^{11}}$
$D = \dfrac{2^{50}}{2^{34}}$
$D = 2^{16}$