Question

Quanto dá: 4+x ( x-4) = x

Answer 1

4 + x (x - 4) = x
4 + x² - 4x = x
4 + x² - 4x - x = 0
4 + x² - 5x = 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
          2.1

x = 5 + 3 = 8/2 = 4
        2

x = 5 - 3 = 2/2 = 1
       2

Resp.: x = 4; x = 1