Explicație pas cu pas:
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[tex]\it b) \\ \\ m_a=\dfrac{x+y}{2} \Rightarrow 18\sqrt2=\dfrac{6\sqrt2+y}{2}\Big|_{\cdot 2} \Rightarrow 36\sqrt2=6\sqrt2+y\Big|_{-6\sqrt2} \Rightarrow y=30\sqrt2[/tex]
