Respostas

2013-09-16T18:33:11-03:00
X = - (-4) +- raiz (-4)² -4*1*(-5) /2*1
x =4 +- raiz 16 +20 /2
x = 4 +-raiz 36 / 2
x = 4 +-6/2
x1 = 4+6 /2
x1 = 10/2 => 
x1 = 5


x2 = 4 -6/2
x2 = -2/2 =>
x2 = -1
24 3 24
2013-09-16T18:35:05-03:00
a=1 b=-4 c=-5
Δ=b²-4ac
Δ=(-4)²-4.1.(-5)
Δ=16+20
Δ=36

x=-b±√Δ/2.a
x=-(-4)±√36/2.1
x= 4±6/2

x'= 4+6/2=10/2=5
x''= 4-6/2=-2/2=-1

S(5,-1)
40 4 40