(5/2+1/6-2)-(3+1/6-5/2)+2/5
(5/2+1/6-2)-(3+1/6-5/2)+2/5
(5/2+1/6-2)-(3+1/6-5/2)+2/5
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$\small \left(\dfrac{5}{2}+\dfrac{1}{6}-2\right)-\left(3+\dfrac{1}{6}-\dfrac{5}{2}\right)+\dfrac{2}{5}=$
$\small =\left(\dfrac{15+1-12}{6}\right)-\left(\dfrac{18+1-15}{6}\right)+\dfrac{2}{5}=$
$\small =\dfrac{4}{6}-\dfrac{4}{6}+\dfrac{2}{5}=$
$\small =0+\dfrac{2}{5}=$
$\small =\dfrac{2}{5}$