Question

Qual a Conta que Faz com 2x²+x-1=0
So que Bem Elaborada

Answer 1

2x² + x - 1 = 0

a = 2; b = 1 e c = -1

$\displaystyle \mathsf{\Delta = b^2 - 4.a.c}\\ \displaystyle \mathsf{\Delta = (1)^2 - 4.(2).(-1)}\\ \displaystyle \mathsf{\Delta = 1 + 8}\\ \displaystyle \mathsf{\Delta = 9}\\ \\ \displaystyle \mathsf{x = \frac{-b \pm \sqrt{\Delta}}{2a}}\\ \\ \displaystyle \mathsf{x = \frac{-1 \pm 3}{4}}\\ \\ \displaystyle \mathsf{x' = \frac{1}{2}}\\ \\ \displaystyle \mathsf{x'' = -1}$

Resposta: x = 1/2 ou x = -1