Răspuns:
a)
Explicație pas cu pas:
a)
[tex] \frac{x {}^{2} - 18x + 81 }{x {}^{2} - 81} = \frac{(x - 9) {}^{2} }{(x - 9) \times (x + 9} = \frac{ \times - 9}{x + 9} [/tex]
b)
[tex] \frac{x {}^{2} - 36 }{x {}^{2} - 12x + 36 } = \frac{(x - 6) \times (x + 6}{(x - 6) {}^{2} } = \frac{x + 6}{ \times - 6} [/tex]
d)
[tex] \frac{x {}^{2} + 10x - 25 }{x {}^{3} - 25x} = \frac{(x + 5) {}^{2} }{x \times (x {}^{2} - 25 } = \frac{(x + 5) {}^{2} }{x \times (x - 5) \times (x + 5)} = \frac{x + 5}{x \times (x - 5)} = \frac{x + 5}{x {}^{2} - 5x} [/tex]
e)
[tex] \frac{x {}^{3} - 49x }{x {}^{3} + 14x {}^{2} + 49x} = \frac{x \times (x {}^{2} - 49) }{x \times (x {}^{2} + 14x + 49) } = \frac{(x - 7) \times (x + 7)}{(x + 7) {}^{2} } = \frac{x - 7}{x + 7} [/tex]
