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Ẩn danh

a: \(\left(5,3-2,8\right)-\left(4+5,3\right)\)

\(=5,3-2,8-4-5,3\)

=-2,8-4=-6,8

b: \(-0,75+\dfrac{1}{2}:\left(\dfrac{2}{3}-\dfrac{5}{12}\right)\)

\(=-0,75+\dfrac{1}{2}:\dfrac{3}{12}\)

\(=-\dfrac{3}{4}+\dfrac{1}{2}\cdot4=-\dfrac{3}{4}+2=\dfrac{5}{4}\)

c: \(\left(-\dfrac{2}{3}\right)^2\cdot71,68+18,32\cdot\dfrac{4}{9}\)

\(=\dfrac{4}{9}\left(71,68+18,32\right)\)

\(=\dfrac{4}{9}\cdot90=40\)

d: \(120\%-\dfrac{3}{14}-\left(\dfrac{6}{5}-2\dfrac{3}{14}\right)\)

\(=\dfrac{6}{5}-\dfrac{3}{14}-\dfrac{6}{5}+2+\dfrac{3}{14}\)

=2