Question

Aratati ca :
   
4x la a 2 a -9         2x+3
-----------------------= ---------------------  , unde x apartine R \ {-1,1,5}
2x la a 2 a -x-3      x+1

Answer 1

$\frac{4x^2-9}{2x^2-x-3} = \frac{(2x-3)(2x+3)}{(2x-3)(x+1)} = \frac{2x+3}{x+1}$

La numarator descompunem $a^2-b^2=(a-b)(a+b)$