Question

How do you simplify `3sqrt5 * sqrt5`?

Answer 1

`15`

Explanation:

Don't be confused by what `3sqrt5` means. It is just the multiplication of `3` and `sqrt5`, so `3sqrt5=3*sqrt5`.

Therefore `3sqrt5*sqrt5=3*sqrt5*sqrt5`.

We see that `sqrt5*sqrt5=5`, so our expression becomes

`3sqrt5*sqrt5=3*(sqrt5*sqrt5)=3*5=15`.