6: \(\left(\dfrac{11}{4}\cdot\dfrac{-2}{9}-\dfrac{7}{9}\cdot\dfrac{11}{4}\right):\dfrac{33}{8}\)
\(=\dfrac{11}{4}\left(-\dfrac{2}{9}-\dfrac{7}{9}\right)\cdot\dfrac{8}{33}\)
\(=\dfrac{11}{4}\cdot\left(-1\right)\cdot\dfrac{8}{33}\)
\(=-\dfrac{11}{33}\cdot\dfrac{8}{4}=-\dfrac{2}{3}\)
7: \(6,7-\left(-4,2\right)+\left(-6,7\right)-14,2+25,3\)
\(=\left(6,7-6,7\right)+\left(4,2-14,2\right)+25,3\)
=25,3-10
=15,3
8: \(\left(3,5-52,6\right)-\left(47,4-6,5\right)\)
\(=3,5-52,6-47,4+6,5\)
\(=\left(3,5+6,5\right)-\left(52,6+47,4\right)\)
=10-100
=-90
9: \(4,7\cdot\left(-0,25\right)-99,75\cdot4,7\)
\(=4,7\left(-0,25-99,75\right)\)
\(=4,7\left(-100\right)=-470\)
