a/ \(7x-3x=3,2\)
\(\Rightarrow4x=3,2\Rightarrow x=\dfrac{3,2}{4}=0,8\)
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b/ \(\dfrac{2}{3}x-\dfrac{1}{2}x=\dfrac{5}{12}\)
\(\Rightarrow\left(\dfrac{2}{3}-\dfrac{1}{2}\right)x=\dfrac{5}{12}\)
\(\Rightarrow\dfrac{1}{6}x=\dfrac{5}{12}\Rightarrow x=\dfrac{5}{12}:\dfrac{1}{6}=\dfrac{5}{2}\)
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