Question

resolva as equecoes quadráticas a) -x2 - 6x - 8 = 0
b) x2 - 5x + 6 = 0
c) -x2 - 4x + 12 = 0

Answer 1

a
-x² - 6x - 8 = 0
x²  +6x + 8 = 0
delta = 36 - 32 = 4 ou +-V4 = +-2 ****

x = ( -6 +-2)/2
x1 = -4/2 = -2***
x2 = -8/2 = -4 ***

b
x² - 5x + 6 = 0
25 - 24 = 1 ou +-V1 = +-1 ****

x = ( 5 +- 1)/2
x1 = 6/2 = 3 ***
x2 = 4/2 = 2 ***

c
-x² - 4x + 12 = 0
x² + 4x - 12 = 0
delta = 16 + 48 = 64 ou +-V64 = +-8 ****

x = ( -4 +-8)/2
x1 = 4/2 = 2 ****
x2 = -12/2 = -6 ****