a)

$\frac{36}{32}\cdot \frac{24}{27}=\frac{9}{8}\cdot \frac{8}{9}=1$

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b)

$\frac{72}{78}\cdot \frac{52}{54}=\frac{36}{39}\cdot \frac{26}{27}=\frac{9\cdot 4}{13\cdot 3}\cdot \frac{13\cdot 2}{9\cdot 3}=\frac{4}{3}\cdot \frac{2}{3}=\frac{8}{9}$

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c)

$\frac{12}{25}:\frac{18}{10}=\frac{12}{25}:\frac{9}{5}=\frac{{\bcancel{12}}^4}{{\cancel{25}}_5}\cdot \frac{{\cancel{5}}^1}{{\bcancel{9}}_3}=\frac{4}{15}$

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d)

$\frac{48}{14}:\frac{40}{56}=\frac{24}{7}:\frac{5}{7}=\frac{24}{\cancel{7}}\cdot \frac{\cancel{7}}{5}=\frac{24}{5}=4\frac{4}{5}$

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e)

$3\frac{3}{5}\cdot \left(-2\frac{2}{9}\right)=\frac{{\cancel{18}}^2}{{\bcancel{5}}_1}\cdot \left(-\frac{{\bcancel{20}}^4}{{\cancel{9}}_1}\right)=-8$

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f)

$\left(-5\frac{1}{3}\right)\cdot \left(-6\frac{3}{4}\right)=\frac{{\cancel{16}}^4}{{\bcancel{3}}_1}\cdot \frac{{\bcancel{27}}^9}{{\cancel{4}}_1}=36$

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g)

$\left(-1\frac{3}{4}\right):1\frac{2}{5}=-\frac{7}{4}:\frac{7}{5}=-\frac{{\cancel{7}}^1}{4}\cdot \frac{5}{{\cancel{7}}_1}=-\frac{5}{4}=-1\frac{1}{4}$

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h)

$6\frac{2}{3}:\left(-4\frac{4}{9}\right)=\frac{20}{3}:\left(-\frac{40}{9}\right)=\frac{{\cancel{20}}^1}{{\bcancel{3}}_1}\cdot \left(-\frac{{\bcancel{9}}^3}{{\cancel{40}}_2}\right)=-\frac{3}{2}=-1\frac{1}{2}$