Question

x ao quadrado - 3 x - 4

como resolver??
equacao 2° grau

Answer 1

$x^2 - 3x - 4 = 0$

$\boxed{\Delta = b^2-4ac = (-3)^2-4*(1)*(-4) = 9 + 16 = 25}$

$\boxed{x = \frac{-b\pm \sqrt{\Delta} }{2a} \to x = \frac{3\pm5}{2} \to \left\{\begin{array}{ccc}x' = \frac{3+5}{2} = \frac{8}{2} = 4 \\ \\ x'' = \frac{3-5}{2} = \frac{-2}{2} = -1 \end{array}\right}$

Espero ter ajudado. :))