jkgckgjcytrxhfxjtxuyfutrxgddxhytxjxciut

`a)` `2/5 - 3/8 + 7/6`

`=` $\dfrac{2.8.6}{240}-\dfrac{3.5.6}{240}+\dfrac{7.5.8}{240}$

`=96-90+280=286`

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`b)` `2/5+(5/7+ -2/3)`

`=(2/3 - 2/3)+5/7`

`=5/7`

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`c)` `-3/7 . 2/5 + 2/5 . 10/7`

`=2/5(-3/7 + 10/7)`

`=2/5 . 7/7`

`=2/5`