# How do you simplify #root7(640 )#?

##### 1 Answer

Dec 23, 2016

#### Answer:

#### Explanation:

There are a couple of properties that hold for any

#root(n)(ab) = root(n)(a)root(n)(b)" "# when#a, b >= 0#

#root(n)(a^n) = a" "# when#a >= 0#

Factorising

#640 = 2^7*5#

So:

#root(7)(640) = root(7)(2^7*5) = root(7)(2^7)*root(7)(5) = 2root(7)(5)#