Question

resolva a equação:
(x-2) (x+2) = 2x - 1

Answer 1

(x-2) (x+2) = 2x - 1

x² - 2² = 2x - 1

x² - 4 - 2x + 1 = 0

x² - 2x - 3 = 0 ¨¨¨¨¨¨¨¨(Báskara)

Δ= b² - 4ac = 4 + 12 = 16

√Δ=+-√16 = +-4

x' = (2-4)/2 = -1

x" = (2+4)/2 = 3

S = {-1 , 3}

Fazendo as substituições:

(x-2) (x+2) = 2x - 1 ¨¨¨¨¨¨¨¨¨x = -1

(-1-2)(-1+2) = 2(-1) - 1 ---> -3 . 1 = -2 -1 ---> -3 = -3

(3-2)(3+2) = 2(3) - 1 ---> 1 . 5 = 6 - 1----> 5 = 5

Answer 2

x2 - 4 = 2x - 1
x2 - 2x -4 + 1 = 0
x2 - 2x - 3 = 0
∆ = 4 + 16
∆ = 16

X1 = ( 2 + 4 ) / 2
X1= 6 / 2
X1 = 3

X2 = ( 2 - 4 ) / 2
X2 = - 2 / 2
X2 = - 1