Question

Simplify the radical 7√7-2√28

Answer 1

7√7-2√28 = 3√7

Explanation:

We have given the expression:

7√7-2√28

We have to simplify the expression.

As we know that:

√28 = √4×7

Then we have,

7√7-2√28 = 7√7-2√4×7

7√7-2√28 = 7√7-2√4×√7

7√7-2√28 = 7√7-2×2×√7

7√7-2√28 = 7√7-4√7

7√7-2√28 = 3√7

Answer 2

`3 √(7)`

EXPLANATION

The given radical is

`7 √(7) - 2 √(28)`

Remove the perfect square from the second radical.

`= 7 √(7) - 2 √(4 * 7)`

`= 7 √(7) - 2 √(4) * √(7)`

`= 7 √(7) - 2 * 2 * √(7)`

`= 7 √(7) - 4 √(7)`

Subtract the like radicals

`= 3 √(7)`