Question

Equaçao do segundo grau : (x-5).(x-3)=-1 ??

Answer 1

(x - 5).(x - 3) = - 1
x² - 3x - 5x + 15 = - 1
x² - 8x + 15 = - 1
x² - 8x + 15 + 1 = 0
x² - 8x + 16 = 0
a = 1; b = - 8; c = 16

Δ = b² - 4ac
Δ = (-8)² - 4.1.16
Δ = 64 - 64
Δ = 0

x = - b +/- √Δ     =  -  (-8) +/- √0
      ---------------      -------------------
              2a                  2.1

x = 8/2
x' = x" = 4

Resp.: x = 4

Answer 2

X^2-3x-5x+15=-1 x^2--8x+15=-1 x^2-8x+16