Question

упростите выражение
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Answer 1

$\Big(\dfrac{6}{y^{2}-9 }+\dfrac{1}{3-y}\Big)\cdot\dfrac{y^{2}+6y+9 }{5} =\Big(\dfrac{6}{(y-3)(y+3)}-\dfrac{1}{y-3} \Big)\cdot\dfrac{(y+3)^{2} }{5}=\\\\=\dfrac{6-y-3}{(y-3)(y+3)}\cdot\dfrac{(y+3)^{2} }{5}=\dfrac{3-y}{(y-3)(y+3)}\cdot\dfrac{(y+3)^{2} }{5} =\boxed{-\dfrac{y+3}{5}}$