Question

How do you evaluate `7\sqrt { 45} + 9\sqrt { 5}`?

Answer 1

`30sqrt5`

Explanation:

`7sqrt45+9sqrt5`

The first thing we need to do is make sure the number inside the radical is the same for both numbers. This means we have to simplify the radical in `7sqrt45` to `5`.

`7sqrt45`
`7sqrt(9*5)`
`7sqrt(3*3*5)`
`7*3sqrt(5)`
`21sqrt(5)`

Now we can add them together:
`21sqrt5+9sqrt5`
`30sqrt5`

Hope this helps!