Question

What are the solutions of the equation: x2 – 1 = 15?

x = ± sqrt 14
x = ± sqrt 15
x = ±4
x = ±8

Answer 1

x = ± 4

Explanation:

Given

x² - 1 = 15 ( add 1 to both sides )

x² = 16 ( take the square root of both sides )

x = ±
`√(16)` = ± 4