Question

Simplify:

square root of 3 times square root of 21

square root of 24

square root of 63

3 square root of 7

None of the above

Answer 1

Answer

3 square root of 7

Explanation

square root of 3 times square root of 21

√3 × √21 = √(3×21)

                  = √63

                  = √(9×7)

                  = √9 × √7

                    = 3 × √7

                   = 3√7

The answer is 3 square root of 7