anonymous one year ago Simplify the radical. 4 square root of 20

1. anonymous

would it be 400..

2. zzr0ck3r

$$4\sqrt{20}=4\sqrt{4*5}=4\sqrt{4}\sqrt{5}$$

3. anonymous

It cant be, these are the option, 5 to the square root of 16 5 to the square root of 8 8 to the square root of 5 16 to the square root of 5

4. anonymous

for $4\sqrt{20}$ i got 17.88

5. anonymous

But that is not one of the options. @emily_wilson

6. anonymous

I see that

7. anonymous

Then what would it be?

8. anonymous

|dw:1441655707709:dw|

9. anonymous

That isnt and option either.

10. anonymous

Do you know how to multiply?

11. anonymous

no

12. PinkSapphire

$8\sqrt{5}$

13. PinkSapphire

This is how you do it.$4\sqrt{20}$Find the greatest factors of 20. $4\sqrt{4\times5}$You can take out the 4 from the square root and it will turn into 2. $4\times 2\sqrt{5}$Now multiply 4 times 2. $8\sqrt{5}$This is in the simplest form it can be.

14. PinkSapphire

Do you understand what I did?

15. zzr0ck3r

If you do not know that $$\sqrt{4}=2$$ and that $$4*2=8$$, I think it would be a good idea to go back and study some old stuff. Else this will not make any sense to you.