Question

resolva as equações do 2° grau:

g)9x²-6x+1 = 0

h)2x²-4x-1 = 0

i)x²-x-12 = 0

Answer 1

Resposta:

i) x^2 -x-12=0

∆=-b^2 -4.a.c

∆=(-1)-4.1.12

∆=1+48

∆=49√49=7

x1/x2=

$\frac{ - b \frac{ + }{ - } \sqrt{delta} }{2.a} = \frac{ - 1 - 7 =}{2.1} = \frac{8}{2} = 4 \\ \frac{ - 1 + 7}{2.1} \: \: \: \frac{6}{2} = 3$

2x^2-4x-1=0

∆=-b^2 -4.a.c

∆=(-4)-4.2.1

∆=16+8

∆=24

x¹/x²= x1= 2,2247... x2=-0,2247

9x^2-6x+1=0

∆=(-6)-4-9.1

∆=36-36

∆=0