Question

Equação de 2 grau :
1) 2x²-8x+8=0
2) x²-4x-5=0
3) -x²+x+12+0

Answer 1

1
2x² - 8x + 8 = 0
delta = 64 - 64 = 0 
DELTA = 0
x = -b/2a
x = 8/4  = 2 ****
x1 = x2 = 2 ****

2
X² - 4X - 5 = 0
DELTA = 16 + 20 = 36 OU +-v36 = +- 6 ****
X = ( 4 +-6)/2
X1 = 10/2 = 5 ****
X2 = -2/2 = -1 ****

3
-X² + X + 12 = 0
X² - X - 12 = 0
DELTA = 1 + 48  = 49 OU +-v49  = +-7 ****

X = ( 1 +- 7)/2
X1 = 8/2 = 4 ***
X2 = -6/2 = -3 ***