Question

BASKHARA EQUAÇÃO 2 GRAU. x2-7x-8=0 (POR DELTA)

Answer 1

$x^{2}$ - 7x - 8 = 0

a = 1; b = -7; c = -8

Δ = $b^{2}$ - 4.a.c
Δ = $(-7)^{2}$ - 4.1.-8
Δ = 49 + 32
Δ = 81

x = $\frac{-(-7) +- \sqrt{81} }{2 . 1}$
x = $\frac{7 +- 9}{2}$

x' = $\frac{7 + 9}{2} = \frac{16}{2} = 8$
x" = $\frac{7 - 9}{2} = \frac{-2}{2} = -1$

S = {8, -1}

Answer 2

x^2 - 7x - 8 = 0 a = 1 b = -7 c = -8 ∆ = b^2 - 4ac ∆ = (-7)^2 - 4.1.(-8) ∆ = 49 + 32 ∆ = 81 x = (-b +-√∆)/2a x = (-(-7) +-√81)/2.1 x = (7 +-9)/2 x' = (7+9)/2 = 16/2 = 8 x" = (7 - 9)/2 = -2/2 = -1 S = {8,-1}