Respostas

2014-07-17T20:49:39-03:00
A) x(x-5)=374

x² - 5x - 374 = 0
a= 1 b= -5 c= -374
Δ=b²-4ac
Δ=(-5)²-4.1.(-374)
Δ= - 353 inexistem raízes reais

b) x² - 14x + 48 = 0
a= 1 b= -14 c= 48
Δ=b²-4ac
Δ=(-14)²-4.1.48
Δ=196-192
Δ=4

x=-b+/-√Δ/2a
x=-(-14)+/-√4/2
x=14+/-2/2
x'=16/2 = 8
x"=12/2 = 6

Xv=-b/2a
Xv=-(-14)/2
Xv=14/2
Xv= 7

Yv=-Δ/4a
Yv=-4/4
Yv= -1

Y= C
Y= 48