Answer:
x = 1 ± 3[tex]\sqrt{2}[/tex]
Step-by-step explanation:
Given
(x - 1)² - 18 = 0 ( add 18 to both sides )
(x - 1)² = 18 ( take the square root of both sides )
x - 1 = ± [tex]\sqrt{18}[/tex] = ± [tex]\sqrt{9(2)}[/tex] = ± 3[tex]\sqrt{2}[/tex] ( add 1 to both sides )
x = 1 ± 3[tex]\sqrt{2}[/tex], thus the exact solutions are
x = 1 - 3[tex]\sqrt{2}[/tex]
x = 1 + 3[tex]\sqrt{2}[/tex]