Respostas

2013-09-24T14:50:57-03:00
-x² +11x-18=0

a) -x²  b)11 c)-18

Fórmula de Bhaskara:
valor de Delta:                     valor de X:
Δ = b² - 4.a.c                      x= -b±√Δ / 2*a
Δ = (-11)²-4*-1*-18=              x= -11±√49 / 2.-1
Δ = 121+4*-18=                   x=-11±7 / -2
Δ = 121-72=                        x'= -4/-2 = 2
Δ =49                                 x"=-18/-2 = 9