Question

- x2 + 8x - 7 = 0 ????

Answer 1

Ola

-x²+8x-7=0

Δ=b²-4.a.c
Δ=8²-4.(-1).(-7)
Δ=64-28
Δ=36

X= -b + ou -√Δ/2.a
X=-8 + ou -√36/2.-1
X= -8 + ou -6/-2
X¹= -8 + 6/ -2= -2/-2= 1
X²= -8-6/-2= -14/ -2= 7

raízes ( 1 e 7)

Answer 2

Eaew!!



Equação do 2° grau.


-x² + 8x - 7 = 0



a = -1
b = 8
c = -7


∆ = b² - 4.a.c


∆ = 8² - 4.(-1).(-7)
∆ = 64 - 28
∆ = 36


X = -b ± √∆/2.a

X = -8 ± √36/2.(-1)

X = -8 ± 6/-2

X = -8 - 6/-2 = -14/-2 = 7

X = -8 + 6/-2 = -2/-2 = 1



S={ 7, 1 }