Question

x² - 2x - 3 =0 alguém pode ajudar??

Answer 1

x² - 2x - 3 = 0
delta = 4 + 12 = 16 ou +-V16 = +-4 ***

x = ( 2 +-4)/2
x1 = 6/2 = 3 ***
x2 -2/2 = -1 ***

Answer 2

x² - 2x - 3 = 0

a = 1, b = - 2, c = - 3

$\Delta =b^2-4.a.c\\\Delta =(-2)^2-4.1.(-3)\\\Delta =4+12\\\Delta =16\\\\\\x= \dfrac{-b \pm \sqrt{ \Delta } }{2.a} \\\\\\\\x= \dfrac{2 \pm 4 }{2}\\\\\\\boxed{x'=3}\boxed{x''=-1 }$


Forte abraço!