Question

x2 +9 +20=0 ajudem pfv

Answer 1

x² + 9x + 20 = 0

∆ = b² - 4ac
∆ = 81 - 80
∆ = 1

X = (-b ± √∆) ÷ 2a
X = (-(+9) ± 1) ÷ 2×1

X' = (-9 + 1) ÷ 2 = -4
ou
X" = (-9 -1) ÷ 2 = -5

Answer 2

x^2+9x + 20 = 0
a= 1; b = 9; c = 20
∆ = b^2-4ac
∆ = 9^2-4.1.20
∆ = 81-80
∆= 1

x = [-b+/- √∆]/2a
x = [-9 +/- 1]/2.1
x'= [-9+1]/2 = -8/2 = - 4
x"= [-9-1]/2 = -10/2 = - 5

R.: (- 4 ; - 5)