Question

resolva as equações

a)x²+5x+6=0
b)x²-5x-6=0
c)2x²-5x+6=0
d)-x+5x-6=0

Answer 1

a) x^2+5x+6=0
delta=b^2-4ac
delta=5^2-4.1.6
delta=25-24
delta=1
x=-b-/+ raiz de delta/2a
x=-5-1/2.1
x=-6/2
x=-3
x=-5+1/2.1
x=-4/2
x=-2
b) x^2-5x-6=0
delta=b^2-4ac
delta=(-5)^2-4.1.(-6)
delta=25+24
delta=49
x=-b-/+ raiz de delta/2a
x=-(-5)-7/2.1
x=5-7/2
x=-2/2
x=-1
x=-(-5)+7/2.1
x=5+7/2
x=12/2
x=6
c) 2x^2-5x+6=0
delta=b^2-4ac
delta=(-5)^2-4.2.6
delta=25-48
delta=-23
delta negativo, não há raízes reais
d) -x^2+5x-6=0
delta=b^2-4ac
delta=5^2-4.(-1).(-6)
delta=25-24
delta=1
x=-b-/+ raiz de delta/2a
x=-5-1/2.(-1)
x=-6-/-2
x=3
x=-5+1/2.(-1)
x=-4/-2
x=2