Question

5. Resolva as seguintes equações do segundo grau.

a) 2x2

– 47 = 3

b) 5x2

– 15x = 0

c) x² + 9x + 8 = 0

d) 3 x² - 15 x + 12 = 0​

Answer 1

Resposta:

a)2x²-50=0

2x²/2-50/2=0/2

x²-25=0

x²=25

_/x²=_/25

_/x²=+/-5

b)5x-15=0

5x=15

x=15/5

x=5

c)Delta=9²-4.1.8

Delta=81-32

Delta=49

x¹=-9+7/2=-2/2=-1

x¹¹=-9-7/2=-16/2=-8

d)Delta=-15²-4.3.12

Delta=225-144

Delta=81

x¹=15+9/6=24/6=1

x¹¹=15-9/6=6/6=1