Question

5) Calcule o valor das raízes das equações abaixo:
a) - x ² + 2x +3 = 0
b) x ² + x – 6 = 0
c) 2x ² + 5x – 7 = 0

Answer 1

Resposta:

a) - x ² + 2x +3 = 0

delta=4+12=16

x=-2+4/-2=2/-2=-1

x=-2-4/-2=-6/-2=3

(-1,3)

b) x ² + x – 6 = 0

delta=1+24=25

x=-1+5/2=4/2=2

x=-1-5/2=-6/2=-3

(-3,2)

c) 2x ² + 5x – 7 = 0

delta=25+56=81

x=-5+9/4=4/4=1

x=-5-9/4=-14/4=-3,5

(1 , -3,5)