a) x!=0
x+1!=0 => x!=-1
2x-4!=0=> 2x!=4 => x!=2
=> x€ R\{-1,0,2}
b)
[tex]( \frac{(x + 1) \times (x + 1)}{x(x + 1)} - \frac{x(x - 1)}{x(x + 1)} + \frac{1 - x}{ {x}^{2} + x } ) \times \frac{ {x}^{2} + x3 }{2x - 4} [/tex]
[tex] \frac{ {x}^{2} + 2x + 1 - {x}^{2}+x + 1 - x}{x(x + 1)} \times \frac{ {x}^{2} + 3x }{2x - 4} [/tex]
[tex] \frac{2x + 2}{x(x + 1)} \times \frac{x(x + 3)}{2(x - 2)} [/tex]
[tex] \frac{x + 3}{x - 2} [/tex]
c)
x-2/x+3
x-2/x-2
din cele 2 relatii de mai sus => x-2/x+3-x+2
x-2/5 => x-2€ D5
x-2€{-5,-1,1,5}
x€{-3,1,3,7}
