Question

2) Resolva as equações do 2 grau completas:
a) x² - 4x - 5 = 0
b) x² - 8x + 12 = 0
c) x² - 5x + 6 = 0
d) x² - 5x + 8 = 0
e) x² + 2x - 8 = 0
f) 2x² - 8x + 8 = 0
g) -x² + 6x - 5 = 0

Answer 1

Resposta:

a) S = {-1, 5}

b) S= {2, 6}

c) S = {3, 2}

d) S = {1,18; 3,82}

e) S = {-4, 2}

f) S = {2, 2}

g) S = {5, 1}

Explicação passo-a-passo:

Delta = b² - 4ac

X = -b +- raiz de Delta/2a

a) x² - 4x - 5 = 0

Delta = 36

X = 4 +- 6/2

-1 e 5

b) x² - 8x + 12 = 0

Delta = 16

X = 8 +- 4/2

2 e 6

c) x² - 5x + 6 = 0

Delta = 1

X = 5 +- 1/2

3 e 2

d) x² - 5x + 8 = 0

Delta = 7

X = 5 +-2,6457513111/2

1,1771243445 e 3,8228756556

e) x² + 2x - 8 = 0

Delta = 36

X = -2 +- 6/2

-4 e 2

f) 2x² - 8x + 8 = 0

Delta = 0

X = 8 +- 0/4

2 e 2

g) -x² + 6x - 5 = 0

Delta = 16

X = -6 +- 4/-2

5 e 1