Question

What is the square root of 5 plus the square root of 20?

Answer 1

`= color(blue)(3sqrt5`

Explanation:

Simplifying `sqrt20` by prime factorisation:

`sqrt20 = sqrt(2^2 *5)=color(blue)(2sqrt5`

The expression can now be written as
`sqrt 5 +sqrt20 = sqrt5 +color(blue)(2sqrt5`

`sqrt5 +2sqrt5 = color(blue)(3sqrt5`