Question

Como resolver a equção x elevado ao quadrado - 2x -3=0

Answer 1

Olá.

$\cdot \: \mathsf{x^{2} - 2x - 3 = 0}$

$\boxed{a = 1 \: ; \: b = -2 \: ; \: c = -3}$

$\mathsf{\triangle = b^{2} - 4ac} \\ \\ \mathsf{\triangle = 4 - 4 \times (1) \times (-3)} \\ \\ \mathsf{\triangle = 4 + 12} \\ \\ \mathsf{\triangle = 16}$

$\mathsf{x = \dfrac{-b \pm \sqrt{\triangle}}{2a}} \\ \\ \mathsf{x_{1} = \dfrac{2 + 4}{2} = 3} \\ \\ \mathsf{x_{2} = \dfrac{2 - 4}{2} = -1}$

$\boxed{S = (1, 3)}$

Bons estudos.