3B:
a: \(x\cdot\dfrac{4}{9}=-\dfrac{8}{27}\)
=>\(x=-\dfrac{8}{27}:\dfrac{4}{9}=\dfrac{-8}{27}\cdot\dfrac{9}{4}\)
=>\(x=-\dfrac{9}{27}\cdot\dfrac{8}{4}=-\dfrac{2}{3}\)
b: \(\dfrac{5}{6}:x=\dfrac{-10}{18}\)
=>\(\dfrac{5}{6}:x=\dfrac{-5}{9}\)
=>\(x=-\dfrac{5}{6}:\dfrac{5}{9}=-\dfrac{9}{6}=-\dfrac{3}{2}\)
2B:
a: \(\dfrac{-3}{25}\cdot\dfrac{4}{17}\cdot\dfrac{5}{-3}\cdot\dfrac{17}{2}\)
\(=\dfrac{3}{25}\cdot\dfrac{5}{3}\cdot\dfrac{4}{17}\cdot\dfrac{17}{2}\)
\(=\dfrac{5}{25}\cdot\dfrac{4}{2}=\dfrac{2}{5}\)
b: \(-\dfrac{8}{15}\cdot\dfrac{13}{16}:\dfrac{13}{30}\)
\(=-\dfrac{8}{15}\cdot\dfrac{13}{16}\cdot\dfrac{30}{13}\)
\(=-\dfrac{8}{16}\cdot\dfrac{30}{15}=-\dfrac{2}{2}=-1\)
c: \(\dfrac{3}{11}\cdot\dfrac{2}{9}+\dfrac{-8}{33}+\dfrac{3}{11}\cdot\dfrac{7}{9}\)
\(=\dfrac{3}{11}\left(\dfrac{2}{9}+\dfrac{7}{9}\right)-\dfrac{8}{33}\)
\(=\dfrac{3}{11}-\dfrac{8}{33}=\dfrac{1}{33}\)
d: \(\dfrac{-11}{25}\cdot\dfrac{2}{3}-\dfrac{-1}{6}+\dfrac{-2}{3}\cdot\dfrac{14}{25}\)
\(=\dfrac{2}{3}\left(-\dfrac{11}{25}-\dfrac{14}{25}\right)+\dfrac{1}{6}\)
\(=-\dfrac{2}{3}+\dfrac{1}{6}=-\dfrac{1}{2}\)
