What is the simplest radical form of (4sqrt(90)) /( 3sqrt(18))?

1 Answer
Apr 6, 2018

4/3sqrt2

Explanation:

We should simplify each root individually.

sqrt90=sqrt(9*10)

Recall that sqrt(a*b)=sqrtasqrtb, so

sqrt(9*10)=sqrt3sqrt10=3sqrt10

Now,

sqrt18=sqrt(9*2)=sqrt9sqrt2=3sqrt2

Thus, we have

(4(3)sqrt10)/(3(3)sqrt2)=(12sqrt10)/(9sqrt2)

Recalling that sqrta/sqrtb=sqrt(a/b), sqrt(10)/sqrt2=sqrt(10/2)=sqrt5

Moreover, 12/9=4/3.

So, the simplest form is

4/3sqrt2