Respostas

2014-05-06T11:22:46-03:00
X´=5 e x´´=-4
Δ=(b)² - 4*a*c = (-1)² - 4*(1)*(-20)=1+80=81...√Δ= 9
x´=1+9/2=5
x´´=1-9/2=-4