Question

Aratati ca $<var>\frac{x^{3}+x^{2}-9x-9 }{x^{3}-x^{2}-9x+9}=\frac{x+1}{x-1}</var>$ , pentru oricare x apartine R - {-3; 1; 3}

Answer 1

$E(x)= \frac{ x^{2} (x+1)-9(x+1)}{ x^{2} (x-1)-9(x-1)}$

$E(x)= \frac{ (x^{2} -9)(x+1) }{( x^{2} -9)(x-1)}$$E(x)= \frac{x+1}{x-1}$