Question

Sendo x1 e x2 as raizes da equacao 5x2-7x-11=0,calcule o valor de cada uma das expressoes:

ex:
a:x1+x2=7/5

b:x1×x2=

c:1/x1×1/x2=

Answer 1

5 x2 -7 x -11 =0

a x2 +b x +c =0

a=5 , b =-7 , c = -11

x1*x2 = c/a = -11/5

$\frac{1}{x_1} + \frac{1}{x_2} = \frac{x_2*x_1 }{x_1+x_2} = \frac{\frac{c}{a}}{\frac{-b}{a}} = \frac{-c}{b}$

-c/b= -11/7