Question

Calcule as raizes das equações abaixo: x2-3x-4=0

Answer 1

x²-3x-4=0

a=1 b=-3 c=-4

$x= \frac{ -b_{-}^+\sqrt{b^2- 4.a.c}}{2.a} \\ \\ x= \frac{ -(-3)_{-}^+\sqrt{-3^2- 4.1.(-4)}}{2.1} \\ \\ x= \frac{ 3_{-}^+\sqrt{9+16}}{2} \\ \\ x= \frac{ 3_{-}^+\sqrt{25}}{2} \\ \\ x= \frac{ 3_{-}^+{5}}{2}$

$x^I= \frac{ 3+{5}}{2}= \frac{8}{2} =4 \\ \\ x^I^I= \frac{3-5}{2} = \frac{-2}{2} =-1$

$x^I=4 \\ x^I^I=-1$