Question

What is Square root of 780 in simplest radical form?

Answer 1

`2sqrt(195)`

Explanation:

We are instructed to determine the square root. So if we split the given value up into prime factors and look for values we can group as squared, then we have our solution.

Using a prime factor tree.

(Good idea to memorise some of the prime numbers if you can)

If you are ever in aby doubt about what the factors are there is nothing to stop you scribbling down a quick factor tree on the side of your work page.

5, 3 and 13 are prime numbers as `5xx3xx13=195`

Observe that the only number you can pair up as a square is the 2. So we write:

`sqrt(780) " "=" "sqrt(2^2xx195)" "=" "2sqrt(195)`