Question

(21x-7)²=0determinar as raizes dessa equaçãome ajudem pfvr

Answer 1

(21x-7) =

441x² - 294 + 49 = 0

Δ  = 86436 - 86436
Δ = 0 

x = 294 +-√0/882 
x = 294 +-0/882
x = 294/882

x' = 1/3
x'' = 1/3                                  S = { 1/3 }                ok

Answer 2

Vamos lá! (21x - 7)^2 = (21x)^2 - 2.21x.7 + 7^2 = 441x^2 - 294x + 49 = 0 Coeficientes: a = 441, b = -294, c = 49 Delta: ∆ = b^2 - 4ac ∆ = (-294)^2 - 4.441.49 ∆ = 86436 - 86436 ∆ = 0 Raízes: x = -b +- √∆ /2a x = -(-294) +- √0 / 2.441 x = (294 +- 0) / 882 x' = (294 + 0) / 882 x' = 294/882 x' = 1/3 x'' = (294 - 0) / 882 x'' = 294/882 x'' = 1/3 S = {1/3}