Question

quais são as raízes da equação x² -3x-4=0?

Answer 1

Resposta:

S={4,-1}

Explicação passo a passo:

ײ-3×-4=0

∆=(-3)²-4.1.(-4)

∆=9+16

∆=25

×=-(-3)±√25/2.1

×=3±5/2

×'=3+5=8/2=4

×"=3-5=-2/2=-1

Answer 2

x²-3x-4=0

a=1

b=-3

c=-4

∆=b²-4.a.c

∆=-3²-4.1.-4

∆=9+16

∆=25

x=-b±√∆/2a

x1=-(-3)+√25/2.1 => 3+5/2 => x1=8/2=4

x2=-(-3)-√25/2.1 => 3-5/2 => x2=-2/2=-1