square root of 40? (Simplified Radical)

sqrt(40)=sqrt(4*10)=2sqrt(10)

The square root is easy it's just 60

square root of 40

you have to look for a square number that goes into 40

squared numbers are

1, 4, 9 ,16, 25, 36,49,  etc     do you understand where they come from?

1 is no help anyway and the only other one is 4.

$$\sqrt{40}=\sqrt{4\times 10}=\sqrt4\times \sqrt{10}=2\times \sqrt{10}=
2\sqrt{10}$$

Say you were asked to simplify $${\sqrt{{\mathtt{55}}}}$$

Well the only factors (besides 1 and itself) are  11 and 5

neither 11, nor 5 are square numbers.  There are no squar numbers that go into 55 so

$$\sqrt{55}$$     cannot be simplified. 

I hope that helps :)