Question

Resolva a Equação do segundo grau 
X² +7x=0

Answer 1

x²+7x=0
x=-b±√b²-4ac/2a
x=-7±√7²-4.1.0/2.1
x=-7±√49-0/2
x=-7±√49/2
x'=-7±7/2
x'=(-7+7)/2 => x'=0/2 => x'=0
x''=(-7-7)/2 => x''=-14/2 => x''=-7

Answer 2

x² + 7x = 0
a = 1 
b = 7
c = 0

Δ = (-b)² - 4.a.c
Δ = (-7)² - 4.1.0
Δ = 49 - 0
Δ = 49

Dai então
x = -b +- √Δ/ 2a
x = -7 +- √49/ 2
x = -7 +- 7/ 2
x1 = -7+7/ 2 ⇒ x1 = 0
x2 = -7 -7/ 2 ⇒ x2 = -14/ 2 ⇒ x2 = -7
S = {-7,0}
Espero ter ajudado!!