279. $y=2 x^{3}-4 x+2$.

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279. $y=2 x^{3}-4 x+2$.
Solution. $y^{\prime}=\left(2 x^{3}-4 x+2\right)^{\prime}=\left(2 x^{3}\right)^{\prime}-(4 x)^{\prime}+(2)^{\prime}=6 x^{2}-4$.