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\(\dfrac{3}{5}a-\dfrac{1}{5}a=\left(\dfrac{3}{5}-\dfrac{1}{5}\right)a=\dfrac{2}{5}a\) .

1. \(\cfrac{13}{37}x+\cfrac{10}{37}x-\cfrac{15}{37}x=\) [ ].
2. \(\cfrac{72}{326}z-\dfrac{14}{326}z-\dfrac{53}{326}z=\) [ ].
3. \(\dfrac{43}{45}k+\dfrac{3}{45}k-\dfrac{1}{45}k=\) [ ].