Question

como resolver 3x²+11x-4=0

Answer 1

3x² + 11x - 4 = 0
a = 3; b = 11; c = - 4

Δ = b²  -4ac
Δ = 11² - 4.3.(-4)
Δ = 121 - 12.(-4)
Δ = 121 + 48
Δ = 169

x = - b +/- √Δ = - 11 +/- √169
          2a                2.3

x' = - 11 + 13 = 2 (:2) = 1         
          6           6 (:2)    3

x" = - 11 - 13 = - 24 = - 4
          6           6

R.: x = 1/3 e x = - 4

Answer 2

a=3
b=11
c=- 4 
 Δ = b² - 4ac
Δ = 11² - 4 · 3 · (-4)
Δ = 121 + 48
Δ = 169 
  

x = -b +_ √Δ / 2a
x = -11 +_ √169 /6
x = -11 +_13 /6
x' = -11+13 /6
x'= 2/6 ÷ 2 = 1/3
x''= -11 - 13/6
x''= -24/6
x''= -4