a: =9/17(3/7+4/7)=9/17*1=9/17
b: =9/25*(-17-2/3)-9/25*22/3
\(=\dfrac{9}{25}\left(-17-\dfrac{2}{3}-\dfrac{22}{3}\right)=-\dfrac{9}{25}\cdot25=-9\)
c: \(=\dfrac{6}{7}\left(\dfrac{8}{13}+\dfrac{9}{13}-\dfrac{4}{13}\right)=\dfrac{6}{7}\)
d: \(=A\cdot\left(\dfrac{1}{3}-\dfrac{1}{4}-\dfrac{1}{12}\right)=0\)