Odpowiedź:
[tex]a) \: \: \frac{x(x + 4)}{(4 - x)(4 - x)} = \frac{x}{4 - x} [/tex]
[tex]b) \: \: \frac{ {x}^{2} + 5x - 3x - 15}{(3 - x)(3 + x)} = \\ \frac{x(x + 5) - 3(x + 5)}{ - (x - 3)(3 + x)} = \\ \frac{(x + 5)(x - 3)}{ - (x - 3)(3 + x)} = \frac{(x + 5) \times ( - 1)}{3 + x} = \\ - \frac{x + 5}{3 + x} [/tex]
[tex]c) \: \: \frac{2 {x}^{2} + 3x - 2x - 3}{3 {x}^{2} + 2x - 3x - 2} = \frac{x(2x + 3) - (2x + 3)}{x(3x + 2)(3x + 2)} = \\ \frac{(2x + 3)(x - 1)}{(3x + 2)(x - 1)} = \frac{2x + 3}{3x + 2} [/tex]
[tex]d) \: \: \frac{ - {x}^{2} + 5x - 6 }{ - 2 {x}^{2} - x + 10 } = \frac{ - {x}^{2}(x - 3) + 2(x - 3) }{ - 2x(x - 2) - 5(x - 2)} = \\ \frac{ - (x - 3) \times ( - 1)}{2x + 5} = \frac{x - 3}{2x + 5} [/tex]
