Question

Simplify the radical expression 3√5+6√45

Answer 1

`21√(5)`

Explanation:

Pull terms out from under the radical, assuming positive real numbers.

Answer 2

21
`√(5)`

Explanation:

Using the rule of radicals

`√(a)` ×
`√(b)` ⇔
`√(ab)`

Simplifying
`√(45)`

=
`√(9(5))` =
`√(9)` ×
`√(5)` = 3
`√(5)`

Then

3
`√(5)` + 6
`√(45)`

= 3
`√(5)` + 6(3
`√(5)` )

= 3
`√(5)` + 18
`√(5)`

= 21
`√(5)`