Question

mim ajudem por favor ....x² - 2x = 1

Answer 1

x² - 2x = 1
x² - 2x - 1 = 0
a = 1, b = - 2, c = - 1

Δ = b² - 4ac
Δ = (- 2)² - 4 . 1 . (- 1)
Δ = 4 + 4
Δ = 8

x = (- b ± √Δ)/2a
x = (- (- 2) ± √8)/2 . 1
x = (2 ± √8)/2
x = (2 ± 2√2)/2

x' = (2 + 2√2)/2 = 1 + √2
x'' = (2 - 2√2)/2 = 1 - √2

x = 1 + √2
x = 1 - √2