Question

Resolva a equação x2+2x-8=0

Answer 1

x² +2x -8 = 0       a=1     b=2     c=-8

Δ = b² - 4.a.c
Δ = 2² - 4.1.-8
Δ = 4 +32
Δ = 36

x = -b +- √Δ / 2a
x = -2 +- √36/2
x = -2 +- 6/2

x' = -2 +6/2                     x'' = -2 -6/2
x' = +4/2                         x'' = -8/2
x' = +2                            x'' = -4

S = {+2,  -4}