Question

Sejam x1 e x2 as raízes da equação do 2°grau x*2 + 3x – 28 = 0. Determine a soma dos inversos de x1 e x2

Answer 1

x²+3x-28=0

Δ=b²-4ac

Δ=3²-4.1.(-28)

Δ=9+112

Δ=121

x=-b+-√Δ/2a

x=-3+-11/2

x1=-3+11/2

x1=8/2=4

x2=-3-11/2

x2=-14/2=-7

$\frac{1}{x1} + \frac{1}{x2}$

$\frac{1}{4} + ( \frac{ - 1}{7} )$

$\frac{1}{4} - \frac{1}{7}$

$\frac{7 - 4}{28}$

$\frac{3}{28}$