Question

Achar a raiz da equação do 2 grau : X2 +3x - 28=0

Answer 1

x^2+3x-28=0
delta=b^2-4ac
delta=3^2-4.1.(-28)
delta=9+112
delta=121
x=-b-/+ raiz de delta/2a
x=-3-11/2.1
x=-14/2
x=-7
x=-3+11/2.1
x=8/2
x=4
S={(-7, 4)}

Answer 2

x² + 3x - 28 = 0
a = 1; b = 3; c = - 28

Δ = b² - 4ac
Δ = 3² - 4.1.(-28)
Δ = 9 - 4.(-28)
Δ = 9 + 112
Δ = 121

x = - b +/- √Δ  = - 3 +/- √121
          2a                2.1

x' = - 3 + 11 = 8/2 = 4
           2

x" = - 3 - 11 = - 14/2 = - 7
          2

R.: x = 4 e x = - 7
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