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Cthzh
a fost răspuns

Fie expresia E(X)=[tex] \frac{5}{ x^{2} +6} - \frac{4}{ x^{2} -5} [/tex] aduceti expresia E(X)÷(2[tex] x^{2} [/tex]+12)^-1 la forma cea mai simpla

Răspuns :

Emy78
E(x)=[5(x²-5) - 4(x²+6)]/(x²+6)(x²-5)
= (5x²-25-4x²-24)/(x²+6)(x²-5)
= (x²-49)/(x²+6)(x²-5)

E(x):(2x²+12)^(-1)=E(x)·(2x²+12)=2(x²+6)·E(x)=
=2(x²+6)·(x²-49)/(x²+6)(x²-5)=
=2(x²-49)/(x²-5)=
=2(x-7)(x+7)/(x²-5)

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