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Rezolvati va rog frumos ...
( 5 + [tex] \frac{1}{ x^{2} -9} : ( \frac{3}{x + 3 } ) - (\frac{2}{x-3} )[/tex] )



Răspuns :

5+1/(x^2-9)/(3/(x+3))-2/(x-3)=0

 a/b/c/d= a*d/b*c

1/(x^2-9)/(3/(x+3)) = (x+3)/3(x^2-9) dar x^2-9=(x-3)(x+3) =>1/3(x-3)

5 + 1/3(x-3) - 2/(x-3) =
 (5*3(x-3) + 1 - 2*3)/3(x-3)=
 (15x-50)/3(x-3)=0
1/3(x-3)(15x-50)=0 Dam factor comun si inmultim ecuatia cu 3
5(x-3)(3x-10)/3*3=0*3
5(x-3)(3x-10)=0
x-3=0 => x=3 nu convine
3x-10=0 => x=10/3