a)\(\left(-\dfrac{5}{16}+\dfrac{8}{13}\right)-\left(\dfrac{11}{16}-\dfrac{5}{13}-2\right)=-\dfrac{5}{16}+\dfrac{8}{13}-\dfrac{11}{16}+\dfrac{5}{13}+2=\left(-\dfrac{5}{16}-\dfrac{11}{16}\right)+\left(\dfrac{8}{13}+\dfrac{5}{13}\right)+2=-1+1+2=2\)b)\(\left(-\dfrac{5}{7}+\dfrac{2}{9}\right):\dfrac{2}{3}+\left(\dfrac{16}{7}+\dfrac{7}{9}\right):\dfrac{2}{3}=-\dfrac{5}{7}+\dfrac{2}{9}:\dfrac{2}{3}+\dfrac{16}{7}+\dfrac{7}{9}:\dfrac{2}{3}=\left\{\left(-\dfrac{5}{7}+\dfrac{16}{7}\right)+\left(\dfrac{2}{9}+\dfrac{7}{9}\right):\dfrac{2}{3}\right\}=\left(\dfrac{11}{7}+1\right):\dfrac{2}{3}=\dfrac{18}{7}:\dfrac{2}{3}=\dfrac{27}{7}\)
\(\left(-\dfrac{5}{16}+\dfrac{8}{13}\right)-\left(\dfrac{11}{16}-\dfrac{5}{13}-2\right)=-\dfrac{5}{16}+\dfrac{8}{13}-\dfrac{11}{16}+\dfrac{5}{13}+2=\left(-\dfrac{5}{16}+\dfrac{-11}{16}\right)+\left(\dfrac{8}{13}+\dfrac{5}{13}\right)+2=\left(-1\right)+1+2=0+2=2\)
\(\left(-\dfrac{5}{7}+\dfrac{2}{9}\right):\dfrac{2}{3}+\left(\dfrac{16}{7}+\dfrac{7}{9}\right):\dfrac{2}{3}=\left(-\dfrac{5}{7}+\dfrac{2}{9}\right)\cdot\dfrac{3}{2}+\left(\dfrac{16}{7}+\dfrac{7}{9}\right)\cdot\dfrac{3}{2}=-\dfrac{5}{7}+\dfrac{2}{9}\cdot\dfrac{3}{2}+\dfrac{16}{7}+\dfrac{7}{9}\cdot\dfrac{3}{2}=[\left(-\dfrac{5}{7}+\dfrac{16}{7}\right)+\left(\dfrac{2}{9}+\dfrac{7}{9}\right)]\cdot\dfrac{3}{2}=\left(\dfrac{11}{7}+1\right)\cdot\dfrac{3}{2}=\dfrac{18}{7}\cdot\dfrac{3}{2}=\dfrac{27}{7}\)
`(-5/16+8/13)-(11/16-5/13-2)`
`= (-5)/16 + 8/13 + 11/16 + 5/13 + 2`
` = ((-5)/16 - 11/16) + (8/13 + 5/13) + 2`
` = -1 + 1 + 2`
` = 0 + 2`
` =2`
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` (-5/7+2/9):2/3+(16/7+7/9):2/3`
` = (-5/7+2/9)xx3/2+(16/7+7/9)xx3/2`
` = 3/2 xx ( (-5)/7 + 2/9 + 16/7 + 7/9)`
` = 3/2 xx [ ((-5)/7 + 16/7) + (2/9 + 7/9)]`
` = 3/2 xx [ 11/7 + 1]`
` = 3/2 xx 18/7`
` = 27/7`
`#BaoL i n h`