Odpowiedź:
[tex]a)x + \frac{3}{x} = ( - 3) + \frac{3}{( - 3)} = ( - 3) + ( - 1) = - 4 \\ b) - 5 {x}^{2} - x = - 5 \times ( - 3) {}^{2} - ( - 3) = - 5 \times 9 + 3 = - 45 + 3 = - 42 \\ c) - 2x + 5 = - 2 \times ( - 3) + 5 = 6 + 5 = 11 \\ d) \frac{x + 1}{x - 1} = \frac{( - 3) + 1}{( - 3) - 1} = \frac{ - 2}{ - 4} = \frac{1}{2} [/tex]
