freeCodeCamp/guide/english/mathematics/simplifying-square-roots/index.md

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Simplifying Square Roots

Simplifying Square Roots

Let's say you have the radical √363, and you need to simplify it into a both, simplest number, and a number that you can use in specific calculations, where we can do this by trying to find perfect squares within the radical.

So, it's a fact that:

√(x×y) = √x × √y

and this fact allows us to understand that we can seperate the √xy into two separate radicals, √x and √y.

But first, we need to find a factor of 363, that would allow us to pull a perfect square from it. Perfect square numbers include: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144 etc. ,as each of them can become a whole number if these numbers were square rooted.

Now, factors of 363 are: 1, 3, 11, 33, 121 and 363.

If you look, you can see that 121 is among that list, 121×3 is 363, and we can change the radical to show that:

√363 = √(121×3) = √121 × √3

And we can take the square root of 121, where we can turn it into a whole number:

= 11 × √3

Hence, 11√3 is the square root number of 363.

Simplifying Square roots in the Denominator:

Lets' say you have the expression:

2√5

And you wanted to simplify this by removing the radical from the denominator, well you can do this by multiplying this fraction by:

√5√5

Which is equal to one, and you get:

2√5 × √5√5

= 2√55

because a square root multiplied by itself is the number in the square, the denominator is now a whole number, not a radical anymore. The radical still exists in the top, but this is fine in most cases, as the value itself is still exact.

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