Respostas

2014-06-19T23:33:12-03:00
A) X=7 e X= -4
B) X= -2 e X = 5
Use esse site: 
www.calculadoraonline.com.br/equacao-2-grau
  • Usuário do Brainly
2014-06-20T00:12:59-03:00
Z²-3z -28=0
a=1
b=-3
c=-28
Δ=b²-4ac
Δ=9+112
Δ=121
√Δ=11

z'= \frac{3+11}{2} = \frac{14}{2} =7

z"= \frac{3-11}{2} = \frac{-8}{2} =-4

S={ -4, 7 }


-x²+3x+10=0
x²-3x-10=0
a=1
b=-3
c=10
Δ=9+40=49
√Δ=7

x'= \frac{3+7}{2} = \frac{10}{2} =5

x"= \frac{3-7}{2} = \frac{-4}{2} =-2

S={-2,5}