Question

Equação do 2 grau:

4+x(x-4)=x

Answer 1

4 + x² - 4x - x = 0
x² - 5x + 4 = 0
a =1
b = -5
c = 4
Δ = b² - 4ac
Δ = (-5)² - 4.1.4
Δ = 25 - 16
Δ = 9
x = - b + - √Δ/2a
x = -(-5) +- √9/2
x = 5 +- 3 /2
x' = 8/2 ⇒ x' = 4
x" = 2/2 ⇒ x" = 1

S = { 4,1}