Question

The positive root of `sqrt(3"x"^2 + 6)` = 9 is:

Options

• 3

• 5

• 4

• 7

Answer 1

5

Explanation:

`sqrt(3"x"^2 + 6)` = 9

⇒ 3x² + 6 = 81

⇒ 3x² = 75

⇒ x² = 25

⇒ x = ±5