Question

[2x-5] [2x+5]=[x+]2ao cuadrado

 equaçoes do 2 grau

 

Answer 1

$\\ (2x - 5)(2x + 5) = (x + 2)^2 \\ 4x^2 - 25 = x^2 + 4x + 4 \\ 4x^2 - x^2 - 4x - 25 - 4 = 0 \\ 3x^2 - 4x - 29 = 0 \\ \Delta = 16 + 348 \Rightarrow \Delta = 364 \\ x = \frac{- b \pm \sqrt{\Delta}}{2a} \\\\ x = \frac{4 \pm \sqrt{364}}{6} \Rightarrow x = \frac{4 \pm 2\sqrt{91}}{6} \Rightarrow x = \frac{2 \pm \sqrt{91}}{3}\\\\ \boxed{S = \left \{ \frac{2 + \sqrt{91}}{3}, \frac{2 - \sqrt{91}}{3}  \right \}}$