Question

-x²+2x+15=0 alquem pra responder?

Answer 1

- x² + 2x + 15 = 0
a = - 1, b = 2, c = 15

Δ = b² - 4ac
Δ = 2² - 4 . (- 1) . 15
Δ = 4 + 60
Δ = 64

x = (- b ± √Δ)/2a
x = (- 2 ± √64)/2 . (- 1)
x = (- 2 ± 8)/(- 2)
x = 1 ± 4

x' = 1 + 4 = 5
x'' = 1 - 4 = - 3

S = {5, - 3}

Answer 2

-x²+2x+15= 0

a= -1, b= 2, c= 15

delta= b²-4.a.c


delta= 2²-4.(-1).15
delta= 4+60
delta= 64

x= -b±√delta/2.a

x= -2±√64/2.(-1)

x= -2±8/-2

x= -2+8/-2= 6/-2= -3

x= -2-8/-2= -10/-2= 5

s={ -3,5 }


Espero ter ajudado!