Question

Simplify this radical.
V84
2/21
242
4/21
4/42

Answer 1

2√21

Explanation:

√84

84 can be written as 4 × 21.

√(4 × 21)

Distribute the square root to both terms.

√4 × √21

4 is a perfect square.

2 × √21

Answer 2

2√21

Explanation:

√81 is √4 times √21

Since √4 is a perfect square, √4 = 2

We are left with 2 times √21

2√21